June seemed to jump straight into July with an upper-level ridge of high pressure dominating the month's weather. With a hot, moist air mass in place throughout the month, any trigger for showers and storms tended to produce excessive amounts of precipitation. While the month ended as the seventh-warmest June on record at more than 4 degrees above normal, the intense rainfall events managed to steal the weather headlines. The biggest of those events occurred on June 14 in central Oklahoma as heavy storms formed and trained across the northern parts of Oklahoma City. The storms quickly dumped 10-12 inches of rain in what would become a 500-year rainfall event at the 6- and 12-hour intervals. Widespread flooding was reported across Oklahoma City with many residents needing rescue by emergency personnel due to rising floodwaters. Despite the plentitude of heavy rain events, the month still finished with a deficit on a statewide basis and ranked as the 56th wettest June on record.

Even with the abnormal warmth during the month, the January-June statewide temperature average ranked as the 55th coolest such with on record, still a bit less than a half-degree below normal. The January-June statewide precipitation average remained about 2 inches below normal to rank as the 52nd driest on record.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

May's dull beginning gave continued hope that Oklahoma's benign severe weather season would continue. With only three tornadoes during the year's first four months and a relatively quiet first nine days of May, there was substantial reason for optimism. Unfortunately, Mother Nature had other ideas and the floodgates to one of the most violent months in recent memory were thrown open on the 10th. That day saw at least 31 tornadoes in the state, killing two and producing hundreds of million dollars in damage. The severe weather continued unabated virtually every day through the end of the month with innumerable reports of large hail, damaging winds and tornadoes. A hailstorm on the 16th tore a swath of damage through the state from the northwest down through Oklahoma City. Damages from this event were again thought to run into the hundreds of millions of dollars. Other high-count tornado days occurred on the 13th and the 19th. At month's end, the preliminary tornado count was nearing 60, which would place it ahead of the May 2003 count of 59 but still well behind the record of 90 tornadoes during May 1999. Climatologically speaking, the month ended as the 50th dries on a statewide basis and the 57th coolest. The climatological spring - March-May - ended as the 44th warmest and the 30th driest.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

As far as Aprils go, this one was quite tranquil and in general, a bit warm and dry. The statewide average temperature was nearly 2 degrees above normal at 61 degrees, which ranks as the 29th warmest April on record. The state's precipitation total was more than a half of an inch below normal and ranked as the 48th lowest since records began in 1895. Severe weather was muted for the most part. The state did see one twister reported near Beaver, and an 81-mph wind gust occurred at Vance Air Force Base in Enid. There was not an abundance of hail reports during the month, and the largest reported size was 1.75 inches. A light frost occurred in the northwest late, but freezing temperatures had largely abated by the middle of the month for the main body of the state. April marked the first month to finish with above normal temperatures on a statewide basis since November 2009. The January-April period ranked as the 29th coolest on record and the 55th wettest. The year through April was still nearly 2 degrees below normal despite the warm April.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

As far as Aprils go, this one was quite tranquil and in general, a bit warm and dry. The statewide average temperature was nearly 2 degrees above normal at 61 degrees, which ranks as the 29th warmest April on record. The state's precipitation total was more than a half of an inch below normal and ranked as the 48th lowest since records began in 1895. Severe weather was muted for the most part. The state did see one twister reported near Beaver, and an 81-mph wind gust occurred at Vance Air Force Base in Enid. There was not an abundance of hail reports during the month, and the largest reported size was 1.75 inches. A light frost occurred in the northwest late, but freezing temperatures had largely abated by the middle of the month for the main body of the state. April marked the first month to finish with above normal temperatures on a statewide basis since November 2009. The January-April period ranked as the 29th coolest on record and the 55th wettest. The year through April was still nearly 2 degrees below normal despite the warm April.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

That Sunday 75 years ago in the Oklahoma Panhandle began magnificently with bright sunshine, calm winds and plenty of spring warmth. Area residents, so burdened by incessant dust that month, enjoyed the reprieve by flocking outdoors. Picnics, car rides and odd jobs around the farm were tackled with a renewed vigor. The region had suffered a significant dust storm just four days previous on the 10th. It was as if the "Dust Gods," a term used by locals during that period to embody the evil force behind their plight, had averted their gaze from the beleaguered populace. The respite would prove to be short-lived, however, and the calm was soon replaced with the violence of the worst "duster" of the Dust Bowl drought. The date was April 14, 1935, and will be forever remembered as "Black Sunday."

Unlike the sand blows that occurred with the sirocco-like winds from the southwest, the Black Sunday event was one of the less frequent but more dramatic storms borne south on polar air originating in Canada. Rising some 8000 feet into the air, these churning walls of dirt generated massive amounts of static electricity, complete with their own thunder and lightning. Reports of the storm indicate that the cold air from the "Norther" struck first, with the wall of dust following soon thereafter. Temperatures plunged 40 degrees along the storm front before the dust hit. Mr. Ralph H. Guy, National Weather Service cooperative observer in Kenton, Oklahoma, noted about the storm:

"Severe dust storm hit at 4:20 p.m., turning afternoon brightness immediately into midnight darkness, and absolutely zero visibility. It was totally dark and impossible to see without searchlight, for at least 15 minutes...the storm came from the north and northeast and traveled at a very great speed."

Many area residents were caught unaware by this unique storm, remembered by locals at the time as one of only three in living memory that appeared to "roll" as it approached. Those caught out in the open were forced to crawl on hands and knees in search of shelter in the impenetrable darkness, literally unable to see their hands in front of their faces. Cars stalled and stopped in the choking dust, and many thought the end of the world had come.

Associated Press reporter Robert Geiger and photographer Harry Eisenhand were caught 6 miles north of Boise City, Oklahoma. The dust cloud enveloped their car as they raced at 60 miles an hour in an attempt to outrun it. The trip the rest of the way into Boise City took over two hours as they drove with the door open so they could see the edge of the highway. A newspaper report by Geiger the following day would give the era its name, a term eventually used as a measuring stick for the severity of every drought thereafter.

In that report, Geiger wrote:

"Three little words — achingly familiar on a western farmer's tongue — rule life today in the dust bowl of the continent ... 'if it rains.'"

Some survivors claim the term "dust bowl" had been used by locals prior to Geiger's reports, an amalgam of the dust they were suffering and a soup bowl, which was a familiar item due to the prevalence of Depression-era soup kitchen lines. Nevertheless, the popularized term soon spread both nationally and internationally.

Black Sunday storm seemed to mark the peak of the dust storms across the region, although the dust would not stop with that most violent of storms. Several stations in the Oklahoma panhandle reported moderate to heavy dust on 20 days during the month, and light dust on other days. Other areas of Oklahoma were not immune to the dust. The Oklahoma City Airport station noted dust on 18 days during the month.

Black Sunday marked the turning point in the Federal Government's recognition of the soil erosion occurring in the Dust Bowl region, labeling it a "national menace." Hugh Bennett, considered the father of the soil conservation movement, had long tried to draw attention to the farmer's plight. Up to that point, he had been largely ignored, and the Dust Bowl was seen in the nation's capitol as just another facet of the depression. Already scheduled to deliver an address to Congress concerning the matter, he heard tales of the massive Black Sunday storm, spreading its dust towards the east. He stalled his report until the dust settled over Washington D.C. Upon its arrival, many of the Congressmen were horrified at the fine, powdery sand choking their throats and scratching their eyes. Using the moment to full effect, Bennett proclaimed "This, gentlemen, is what I've been talking about." On April 27th, 1935, the Soil Conservation Service (SCS) was created, and placed under the control of Bennett.

A boiling cloud of dust approaches Stratford, Texas. Photo courtesy of NOAA Photo Library, George E. Marsh album.

To read more on the Dust Bowl, please see the Oklahoma Climatological Survey's "Summer 2004" edition of its seasonal summary series Oklahoma Climate:
http://climate.mesonet.org/seasonal_summary.html

Or visit the Norman National Weather Service office's webpage at:
http://www.srh.noaa.gov/oun/?n=blacksunday

And the Dodge City National Weather Service office's webpage at:
http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=ddc&storyid=50702&source=0

March turned out a little cooler and drier than normal according to data from the Oklahoma Mesonet. The statewide average rainfall ended with a deficit of greater than an inch below normal and ranked as the 44th driest on record. The temperature data was similar at more than a degree below normal, which ranked the month as the 55th coolest on record. The biggest stories during March, however, will not come as a shock to those accustomed to Oklahoma's wild weather. The first was a tornado on the eighth that struck the small town of Hammon in Roger Mills County. The EF2-rated twister gave the town a glancing blow and left damaged homes and businesses in its wake. It was also the first tornado to touch down in the state since October 29, 2009. The next major weather event was a late-month snowstorm that dumped from 3-7 inches of snow across the state. Pryor led the state's totals with 11 inches. The final big weather story occurred as the month waned. Temperatures soared into the 90s in western Oklahoma during March's final three days. The heat combined with low humidities and strong winds gusting to over 40 mph to produce extreme fire danger.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

February was gloomy and dark, a perfect companion to the previous two winter months. The statewide average temperature ended more than 6 degrees below normal to rank as the 14th coolest February since 1895. The statewide average precipitation total was nearly an inch above normal and ranked as the 19th highest on record. Several bouts of wintry weather continued the cool weather of the previous two months. All areas of the state received snow at one time or another, and southern Oklahoma received the most thanks to a couple of southerly-track storms. The southeast had generous rains that bolstered their totals for the month to greater than 6 inches in some areas. There was very little in the way of severe weather. A few storms produced a bit of small hail, but most of the inclement weather was of the frozen variety. The climatological winter (December-February) ended as the 17th coolest on record at nearly 4 degrees below normal and the 40th wettest with a surplus of about a third of an inch.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Gary McManus
Associate State Climatologist
Oklahoma Climatological Survey

Two significant ice storms and several heavy snows, including a record-setting 13.5 inches in Oklahoma City during the historic Christmas Eve blizzard, have left Oklahomans wondering where the warm winters of the past 20 years have gone. While Vancouver has had to truck snow in for their Olympic Games, Oklahoma and points even farther south have gotten a crash course in Midwestern-style winters. Oklahomans have no doubt enjoyed that string of warmer winters over the last couple of decades. In fact, 14 of the previous 20 winters in Oklahoma have been above the long-term average in temperature, including the all-time warmest in 1991-92 and the second warmest on record in 1999-00. That is not to say that every winter has been or should be warmer than the last, of course. Natural variability still plays a part in Oklahoma's weather conditions and always will. Even during this string of warmer winters, cold winters will still materialize, such as the current winter and that of 2000-01. Natural variability at times leaves Oklahoma at the mercy of weather patterns from far-off parts of the world. That is exactly what has occurred this season as sea-surface temperatures in the equatorial Pacific Ocean and higher-than-normal pressure over the North Pole has left us chilled in a seemingly perpetual gloom.

The 2009-10 El Niño event, previously forecast to be of moderate intensity, turned out to be the strongest since the 1997-98 "super" El Niño. During a strong El Niño, the storm track shifts to the south during winter and can bring more storm systems across the state. Along with those storm systems comes more cloudiness and precipitation. Those two trends are evident in data from the Oklahoma Mesonet, the state's weather network. The statewide average precipitation total since the beginning of climatological winter (December 1) through February 22 stands at 5.26 inches, a third of an inch above normal and the 29th wettest winter since 1921. The totals from southern Oklahoma are much higher than normal, with southwestern Oklahoma experiencing its 11th wettest winter thus far. Similar totals exist for south central and southeastern Oklahoma. This is exactly the type of pattern expected with El Niño and the southerly shifted storm track.

A casualty of all that cloudiness and precipitation is sunshine, and data from the Oklahoma Mesonet exemplifies that once again. The Mesonet's instruments that measure solar radiation have received a mere 46.2 percent of possible sunshine this winter, the second-lowest total since the Mesonet began in 1994. Only the winter of 1997-98, the second wettest on record and the "super" El Niño winter, was gloomier.

The impact on Oklahoma's temperatures has been to suppress the daytime high temperatures much more than the lows. The average high temperature from the Oklahoma Mesonet this winter has been nearly 6 degrees below normal while low temperatures are less than 2 degrees below normal. The cloudiness helps block solar radiation during the day while trapping heat during the overnight hours. For the winter thus far, the statewide average temperature was 34.6 degrees. Oklahoma City's lowest daily temperature this season has been 6 degrees, which is certainly cold, but nowhere near the sub-zero temperatures seen in its past. The coldest daily temperature reported during Oklahoma City's relatively warm winter last year was also 6 degrees.

Another culprit responsible for our cold winter is a phenomenon known as the Arctic Oscillation (AO), which can shift between negative and positive phases during the span of a couple of weeks. When it is in the negative phase, as it has been for much of the winter, high pressure over the North Pole deflects the bitterly frigid air from that region farther to the south into the interior of the United States. Temperatures in the Arctic region rise tremendously and those farther to the south plummet. The values for the AO Index, which measures the relative strength of the AO, during December were the most negative for that month since record keeping began in 1950, and have dropped to that level again during February. Combine a strongly negative AO with a strong El Niño and you get the historic snows that much of the eastern half of the United States has seen this winter, as well as those in Oklahoma and Texas.

Even as the vagaries of Mother Nature conspire to give us a winter more reminiscent of our past than our present, it is important to remember that a single season or year does not make a trend. Until the weather pattern changes, Oklahomans might see their Midwestern-style winter continue.

Oklahoma's vicious winter still packed a powerful bite during January. A blast of arctic air struck early in the month and brought some of the coldest weather in more than a decade to the state. A couple of weeks of respite were followed by a significant winter storm that dropped 4-10 inches of snow across a large area. The worst of that storm struck southwestern and south central Oklahoma, however, with widespread freezing rain accumulations of three quarters of an inch, devastating the electrical utility infrastructure in those areas. Approximately 180,000 customers were left without power due to the storm. The previous winter blast on January 6-10 saw temperatures drop as low as -6 degrees. Strong winds combined with the frigid air to drop wind chill values into the -20s. Those two winter events helped the month finish as the 31st coolest January on record, dating back to 1895. Preliminary data show the month to be the 51st wettest as well at just a bit below normal, although the frozen precipitation at month's end is not reflected in the January totals.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

(EDITOR'S NOTE: Interviews with the symposium presenters can be arranged upon request or at the presentation with advance arrangements. For more information, call (405) 325-1819 or e-mail amybuchanan@ou.edu.)

NORMAN, Okla. - The University of Oklahoma National Weather Center will host a free, public discussion on the climate and its impacts at 7 p.m. Monday, Feb. 8, as the opening event for the Regional Climate Symposium, "Regional Climate - Monitoring, Modeling, Predicting, and Impacts," being held Feb. 9 and 10 at the National Weather Center.

Lynne Carter, from the Southern Climate Impacts Planning Program at Louisiana State University, will deliver the public address and lead an open discussion about global climate change and what it means regionally and locally.

"With this symposium, we are aiming to increase the awareness and understanding by both the general public and the university community regarding global climate change," said John Snow, dean of the OU College of Atmospheric and Geographic Sciences. "We are fortunate to have the Science Applications International Corporation as a major sponsor of this endeavor.

"The Monday evening session will be structured to provide an opportunity for many outside the scientific community to voice their perspectives on our changing climate. The day-and-a-half of scientific sessions that follow will cover recent research results in this critical area."

The two-day symposium that follows will bring together experts in diverse fields of climate sciences to discuss the state of the science. The scientific sessions, beginning Tuesday morning, will include topics such as observations and monitoring, seasonal and inter-annual effects of climate, modeling and verification, policy and economics.

Also scheduled is a luncheon presentation at noon Tuesday. Gary McManus, associate state climatologist for the Oklahoma Climatological Survey, will deliver the talk, "Global Climate Change and the Implications for Oklahoma."

There is no fee for attending the symposium or the luncheon, but advance registration is required. Registration, a full agenda and directions to the National Weather Center are available online at http://nwc.ou.edu/symposium/2009/ or by calling the OU College of Atmospheric and Geographic Sciences at (405) 325-3095.

The symposium is being supported by a grant from Science Applications International Corporation, with additional support provided by the OU College of Atmospheric and Geographic Sciences and the National Oceanic and Atmospheric Administration Regional Integrated Science and Assessments program at OU.

The National Weather Center is located on OU's Research Campus on the corner of Highway 9 and Jenkins Avenue. It houses a unique confederation of OU, National Oceanic and Atmospheric Administration and state organizations that work together in partnership to improve the understanding of events occurring in Earth's atmosphere over a wide range of time and space scales.

Lynne Carter
Lynne Carter is the program manager of SCIPP at Louisiana State University. Carter is active in climate impacts and adaptation work. She was a member of the writing team for the "2009 Climate Impacts on the United States" document from the Climate Change Impacts Program; was the regional liaison for the U.S. National Assessment of Climate Variability and Change, as the director for a nonprofit organization focused on building resilience and adapting to climate changes with communities; and continues to work in education and outreach around climate issues.

The Southern Climate Impacts Planning Program
SCIPP is a new, climate-research initiative formed to help communities better plan for weather and climate-related disasters in the southern United States, particularly in the face of changing climate. Focusing on the six-state study region of Oklahoma, Texas, Louisiana, Arkansas, Tennessee and Mississippi, SCIPP concentrates on the high frequency of hazardous climatological events that plague the region. This includes extremes in precipitation, both droughts and floods, as well as other hazards, including severe storms and hurricanes. For more information, visit www.southernclimate.org.

Science Applications International Corporation
SAIC is a FORTUNE 500(R) scientific, engineering and technology applications company that uses its deep domain knowledge to solve problems of vital importance to the nation and the world, in national security, energy and the environment, critical infrastructure and health. The company's approximately 45,000 employees serve customers in the U.S. Department of Defense, the intelligence community, the U.S. Department of Homeland Security, other U.S. government civil agencies and selected commercial markets. Headquartered in McLean, Va., SAIC had annual revenues of $10.1 billion for its fiscal year ended Jan. 31, 2009. For more information, visit www.saic.com.

The OU College of Atmospheric and Geographic Sciences
The College of A&GS is composed of three academic units - the Department of Geography, the School of Meteorology and the Geographic Information Science program - in addition to 10 research and service units. It is the college's goal to administer, guide and direct an academic enterprise in geography, geographic information science and meteorology so as to become the international leader in weather- and climate-related education and training, environmental and sustainability studies, research and development and extension and outreach. Three hundred undergraduate students and more than 100 graduate students are enrolled in the college. For more information, visit http://ags.ou.edu.

An historical Christmastime blizzard dominated the weather stories during December, an otherwise dry and cold month. The statewide average temperature ranked as the 10th coolest on record, while the statewide average precipitation ranked as 57th driest. The blizzard struck on Christmas Eve, pounding the state with sleet, freezing rain, snow and winds gusting to over 60 mph. Oklahoma City recorded 13.5 inches of snow, breaking their record for the 24th as well as storm-total and 24-hour snowfall records. The snow was heaviest in central and northeastern Oklahoma, along and to either side of the I-44 corridor. The freezing rain that fell in southwestern Oklahoma combined with the strong winds to produce approximately $2 million in damages to electrical utility infrastructure and left thousands without power during the storm. Preliminary reports indicate at least nine people lost their lives due to the storm. The year ended as the 37th coolest on record and the 31st wettest, a result of an exceptionally cool and wet second half of the year.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

The final month of climatological autumn could not have been more different from the previous two - the unusually wet and cool September and October months were followed by a distinctly dry and warm November. The statewide average precipitation total finished more than 2 inches below normal, the 22nd driest since 1895. The statewide average temperature averaged nearly 5 degrees above normal for the eighth-warmest November on record. The western two-thirds of the state were exceedingly dry with most locations receiving less than a half of an inch of rainfall. Despite the warm and dry month, however, fall finished as the 15th coolest and 18th wettest on record. The first 11 months of the year were on pace to finish a bit cooler and wetter and normal and ranked as the 57th coolest and 29th wettest through November.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Oklahomans have grown accustomed to the fickle weather of the Great Plains, particularly during the transitional months of spring and fall. Many state residents have left the house dressed for a pleasantly warm autumn day, only to be caught unawares by the icy chill of an arctic blast. With experience comes wisdom, however, and Oklahomans have learned to keep a trained eye on the weather forecasts. Imagine the surprise of the state's burgeoning population on November 11, 1911, when weather forecasts were mostly limited to observations passed down the telegraph line, as they witnessed one of the most abrupt temperature swings in the state's 102-year history. On that afternoon, Oklahoma City reached a record high temperature of 83 degrees. Soon thereafter, a "norther" barreled through the state, dropping temperatures 50-65 degrees in the span of a few hours. By midnight, the temperature at Oklahoma City had plunged to a frigid 17 degrees, the record low for that same date. Both records still stand, marking November 11th, 1911, as the only date in state history in which the record high and low temperatures were broken on the same day for a single location. National Weather Service forecasts indicate the milestones will be safe for yet another year. The high temperature for Oklahoma City on the 11th should hover near 65 degrees, and the low is expected to remain in the upper 40s.

November came a bit early this year disguised as October. The month finished nearly 7 degrees below normal to rank as the second coolest October on record. Lots of moisture went along with that cool weather and the statewide average precipitation finished with a surplus of more than 3 inches, enough to rank as the fifth wettest on record. The rainfall amounts became extreme in eastern Oklahoma, exemplified by the 50 reports of flash flooding in that area. The southeastern region had a surplus of over 7 inches that helped it to its second-wettest October on record. Meanwhile, the Panhandle, west central and east central sections of the state experienced their coolest Octobers on record. Severe weather was confined mostly to flooding, but there was a tornado touchdown in Okfuskee County. The twister struck near Weleetka and damaged some roofs but was rated an EF0 on the Enhanced Fujita Scale.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Tempered only by below normal rainfall in the north and west, heavy rains in the southeastern half of the state helped the month to rank as the 32nd wettest September on record. The southeast climate division's average rainfall total was nearly 4 inches above normal and ranked as the sixth wettest on record for that area. On the other hand, north central Oklahoma's average rainfall total was nearly 2 inches below normal and ranked as the 22nd driest on record. The heavy rains were prompted by a pair of upper-level systems that plagued the state for about 10 days in the month's middle. The first system approached from the north and combined with a front to bring heavy rains to the northeast and then the south. The second system formed to the south and meandered about the area for days, peppering the state with oddly moving southeast-to-northwest rains. Several strong cold fronts kept the state on the cool side and the month ranked as the 16th coolest on record. Severe weather was uncommon during the month, although reports of flooding were plentiful, especially in the eastern third of the state.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

The summer doldrums were absent during August with plenty of rainfall and relatively cool weather on tap for Oklahoma. Abundant rains in the north central parts of the state propelled the month to finish as the 25th wettest since 1895. The rains and a few unusually strong fronts helped cool things down from the normal August heat - the month finished as the 21st coolest on record. With the rain came a goodly amount of severe weather, mostly flooding and high wind reports. Cloud-to-ground lightning strikes were especially prevalent with the August storms. The summer season finished a little cool and wet as well, and ranked as the 40th coolest and 48th wettest on record.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

On Monday, August 24 at 7:15 PM CDT, OCS will perform maintenance on a critical system. This will result in about 30 minutes of downtime for all OCS and Mesonet web and FTP sites. Our sites will be back online no later than 8:15 PM. In the event of severe weather, we will postpone this activity.

July's weather was a bit bizarre, even by Oklahoma's standard. A series of cold fronts rescued the state from the blast furnace of summer and even brought welcome rainfall. Cold fronts are not that unusual in Oklahoma, of course, but they generally do not occur on a regular basis during summer, especially July. Despite a period of 12 out of the first 16 days with widespread triple digits, the statewide average temperature finished as the 34th coolest since 1895. Not only were triple-digits present, five of those days saw a good number of readings above 110 degrees, including 115 degrees at Buffalo and Freedom. Those marks tied (Buffalo) and broke (Freedom) those two towns' all-time record highs for any day of any month. The temperatures during the month ranged from 115 degrees at Buffalo and Freedom to 51 degrees at Jay. In addition to the record high temperatures, several record daily low temperatures were also tied or broken. Widespread lows in the 50s were reported on several days. The statewide average precipitation total was the 27th wettest on record. Severe weather for the month was widespread at times with high winds being the most-reported culprit - no tornado touchdowns were reported, however.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

What a difference a night makes. Yesterday afternoon we were discussing the addition of D2 - Extreme Drought in northwestern Oklahoma. Today we know that next week's discussion will center on where to show improvements. The heavy rainfall of the last 24-hours will help ease developing drought conditions in much of the region, although northern parts of the state are still waiting for these beneficial rains.

According to the U.S. Drought Monitor this week, conditions in most of northwestern Oklahoma, with the exception of the Panhandle, was downgraded to "Severe Drought" status (level 2 on the drought scale which ranges from D0 "abnormally dry" to D4 "exceptional drought"). Another area in east central Oklahoma, just north of I-40 near the Arkansas border, was increased to D1 "moderate drought". On the positive side, a large area of D0 in southern Oklahoma was removed this week, where rains had already fallen before the new analysis was published.

The developing drought conditions, while severe, pale in comparison to the effects of a long-lasting drought in South Texas or the D4 "exceptional drought" that plagued our state during 2005-2006. Fortunately, most water supplies were replenished during the intervening wet years so widespread and severe impacts have not yet been reported. With more rainfall in the forecast in the next few days, hopefully we will be able to show improvement in the remaining areas that did not receive much rain yet.

Do Your Part
If you are experiencing drought-related impacts, let us know. E-mail us at drought@mesonet.org or go online to www.drought.gov to the Drought Impact Reporter. Impacts are a critical determinant in defining drought levels on the Drought Monitor, which in turn is used by the USDA as criteria for federal assistance programs. Your reports are vital in helping us pinpoint the most severe conditions, and to avoid improving our depiction too rapidly as conditions improve.

NORMAN, Okla. - The Fred V. Brock Standards Lab - named in honor of one of the early pioneers of the Oklahoma Mesonet, the state's weather network - was dedicated in a reception on Tuesday, June 30, at the National Weather Center, 120 David L. Boren Blvd. on the University of Oklahoma Research Campus.

"Professor Brock was an integral part of implementing both the Oklahoma Mesonet and the Mesonet's calibration laboratory," said Ken Crawford, director of the Oklahoma Climatological Survey. "He always believed the statement 'trust, but verify,' and because of this, the Mesonet and its data became the gold standard for mesoscale surface networks. The fundamentals of his calibration processes are still relied upon today."

The reception included remarks from Crawford; John Snow, OU College of Atmospheric and Geographic Sciences dean; and Charles Doswell, OU School of Meteorology adjunct professor. A plaque honoring Brock, which is located outside the laboratory, also was unveiled during the reception.

"We wanted to show our appreciation for the contributions Brock made during the early days of the Oklahoma Mesonet," said Chris Fiebrich, manager of the Oklahoma Mesonet. "By dedicating the Standards Lab in his name, we hope all future users of Mesonet data recognize his commitment to data quality as well."

The Fred V. Brock Standards Laboratory has been enhanced by support from a number of Brock's colleagues and friends, as well as private-sector companies who design meteorological instrumentation and applications.

Fred V. Brock
Brock designed, developed and operated the National Center for Atmospheric Research's Portable Automated Mesonet; served as professor of meteorology at OU from 1985 to 1997; was a founding member of the Mesonet Steering Committee and first manager of the Oklahoma Mesonet; and was lead author of numerous publications, including Meteorological Measurement Systems (2001). In 2000, Brock was awarded the American Meteorological Society Award for Outstanding Contribution to the Advance of Applied Meteorology.

The Oklahoma Mesonet
The Oklahoma Mesonet is Oklahoma's weather network. The network was designed and implemented by scientists at OU and Oklahoma State University.

The Oklahoma Mesonet measures a large variety of environmental conditions at more than 100 locations statewide. The Mesonet's thousands of sensors are tested and validated in the Fred V. Brock Standards Lab both before and after their field deployment. Because of the continual flow of high-quality observations, the production of millions of decision-making products have been enabled for government agencies, public safety officials, agricultural producers, students, researchers, electric utilities, weather forecasters and private citizens.

The Oklahoma Climatological Survey at the OU National Weather Center receives the observations, verifies the quality of the data and provides the data to Mesonet customers. It takes less than 10 minutes from the time the measurements are acquired until they become available to the public.

For more information about the Oklahoma Mesonet, visit http://www.mesonet.org/. For additional information on the Oklahoma Climatological Survey, visit http://climate.ok.gov/.

Recent rains have certainly helped alleviate dry conditions in Oklahoma, but more are needed to curtail a burgeoning drought at the onset of summer. While not the driest time of the year according to the rain gauge, the summer months are most definitely the driest according to water demand. With growing plants and extreme heat on the prowl, the evapo-transpiration demands can far outpace even normal rainfall during summer. Entering this high-demand period with a deficit is a prime recipe for a drought-filled summer.

The latest U.S. Drought Monitor depiction shows drought spreading in northwestern and north central Oklahoma. The amount of drought in Oklahoma deemed "moderate" has more than doubled since last week. Even though the amount remains small, it shows a tendency for the spread of drought. Rainfs that occurred in late-April thru mid-May quickly ended following that period. North central Oklahoma has had as little as 20 percent of normal precipitation from May 17-June 12. Only portions of southern Oklahoma have had above normal precipitation during that period.

The U.S. Drought Monitor depiction is updated every Thursday and can be found here:
http://www.drought.unl.edu/dm/monitor.html

You can also follow Oklahoma's drought situation with statistics provided by the Oklahoma Mesonet:
http://climate.mesonet.org/rainfall_update.html

Oklahoma's transition from wet and stormy to the summer doldrums, normally seen sometime around mid-June, seemed to occur about a month early. The first half of May provided a couple of month's worth of rainfall in some parts of the state. The weather calmed considerably during the latter half, however, with only a brief interruption by a summer-like storm system. Severe weather was widespread and frequent through the 16th. Abundant reports of large hail and wind gusts greater than 70 mph were accompanied by extensive flooding. Only five confirmed tornadoes touched down during May, one of those being a significant EF2 twister that struck Anadarko. That tornado and the associated rear-flank downdraft winds caused widespread damage in that city. The month as a whole was close to normal with a statewide average of nearly 5 inches of rainfall to rank as the 52nd wettest on record. That statistic is deceiving, however, as most of the northwestern half of the state was below normal. The east's robust rainfall totals between 10-20 inches buoyed the monthly total. The statewide average temperature was a different story, however, falling below normal by more than two degrees to rank as the 19th coolest May since 1895. That propelled the spring season to finish as the 58th coolest on record with slightly below normal temperatures. The January-May period remained well above normal and ranked as the 35th warmest such period on record. The spring season was also the 29th wettest on record while the January-May period was slightly below normal but still ranked as the 45th wettest.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

April was a tumultuous month for weather in Oklahoma, containing everything from a wheat-devastating hard freeze to significant tornadoes to a 500-year rainfall event. The rainfall in general was a drought-buster, and the month finished as the 17th wettest across the state since 1895. The temperatures were cool due to the rains and the incursion of some very cold air masses, ranking as the 50th coolest April on record. Preliminary data place the tornado count at 16 for the month, with five of those twisters considered significant (EF-2 or greater). A cold snap early in the month damaged the state's drought-stressed wheat crop, especially in southern Oklahoma where temperatures plunged into the teens. Non-thunderstorm winds of greater than 70 mph contributed to extreme wildfire conditions early in the month and many homes and structures were destroyed. An outflow boundary on the 29th produced wave after wave of thunderstorms along the Red River and the Oklahoma Mesonet site at Burneyville had a front-row seat. The 12.42 inches of rainfall broke several records, including the daily and monthly record at Burneyville and the Mesonet daily rainfall amount network-wide for any day since its inception in 1994. The deluge also eclipsed several return-period rain levels, such as the 500-year 1-day, 24-hour and 12-hour amounts.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Between 10:50 a.m. Wednesday and 5:10 a.m. Thursday, the Oklahoma Mesonet site at Burneyville recorded 12.89 inches of rainfall. A momentousamount of rain no doubt, and that total is obviously going to break some records.Keep in mind as we discuss these that we are in somewhat uncertain territory due to the different periods Mesonet vs. COOP use in their measurements. There is also the distinction between 24-hour records and daily records. In the end, if we want to stick strictly to midnight-midnight periods, we have a total of 12.42 inches with this event, so we're still safe. We'll go with our "daily" total (7am-7am) of 12.89 inches where appropriate.

So let's go through what records we now believe havefallen.

1. Burneyville daily rainfall - All we have to go by is the Mesonet station since it appears there was never an official Burneyville NWS COOP site. The total obviously shattered the previous daily record for Burneyville, 6.62 inches set on April 28, 2006.
2. Burneyville monthly rainfall - The single day total was enough to best the previous monthly total of 12.01 inches from June 2004. Add in rain from earlier this month and you have a monthly total that currently stands at 15.36 inches.
3. Mesonet daily rainfall - The total shatters the previous daily rainfall mark recorded by the Mesonet of 9.89 inches at Cheyenne on June 14, 1996. The only other totals in view of this one would be the 9.13 inches at Fairview on September 12 of last year and the 9 inches recorded at Fort Cobb during Tropical Storm Erin's recovery on August 18, 2007. A more thorough investigation shows the Burneyville event broke the 24-hour rainfall event for the Mesonet as well. No 24-hour period in the history of the Mesonet had a greater total than 12.89 inches.
4. Oklahoma daily rainfall amount, any network - The total of 12.84 inches has been bested only three times in our recorded history. The rankings:
   • Enid (COOP), October 11, 1973 15.68 inches
   • Cheyenne (COOP), April 4, 1934 13.79 inches
   • Purcell (COOP), May 11, 1950 13.58 inches
   • Burneyville (Mesonet), April 29, 2009 12.89 inches
   • Eufaula 2 SW (COOP), October 31, 1941 12.86 inches
   • Stigler 1 SE (COOP), May 10, 1943 12.32 inches
   • Hee Mountain Tower (COOP), October 13, 1972 12.30 inches
   • Seminole (COOP), April 14, 1945 12.20 inches
   • Meeker (COOP), June 3, 1932 12.18 inches
   • Seminole (COOP), June 22, 1948 12.00 inches
5. Recurrence-interval totals - While these aren't records, they are a good indicator of extreme rainfall events. These are taken from Tortorelli's "Depth-Duration Frequency of Precipitation for Oklahoma" publication.
   

   Recurrence	Interval	Tortorelli	Total
   500-Year	1-Day	12.20	12.89
   500-Year	24-Hour	12.00	12.89
   500-Year	12-Hour	10.80	11.73
   100-Year	6-Hour	6.80	8.58
   100-Year	3-Day	11.60	12.89
   50-Year	7-Day	11.80	12.92

A late-month blizzard kicked all other March weather stories to the curb with northwestern Oklahoma seeing more than 2 feet of snow and drifts taller than the average adult. The storm - which provided the state with snow, sleet, freezing rain, and severe thunderstorms - struck on the 27th and 28th. Preliminary reports from the National Weather Service (NWS) offices in Norman and Amarillo indicate the state's 24-hour snowfall record might have been bested in several locations. The previous record was 23 inches from the Buffalo blizzard of February 1971. The totals indicate the spring snowstorm rivals the worst in state history. Before that late storm system, the month was on its way to being exceedingly warm and dry. Despite the moisture and cold air, however, the month still finished as the 32nd warmest and 58th driest on record. That continues a pattern seen during the previous couple months of 2009, and the first three months of the year now rank as the 19th warmest such period since 1895, and the 33rd driest. Severe weather consisted of standard spring fare - large hail and strong winds. One tornado touched down during the month, a weak EF-0 twister which struck near Pawnee early on the 24th.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

The Oklahoma Climatological Survey joins again with the Oklahoma Insurance Commissioner to host the 4th annual Climate and Loss Mitigation Conference on April 9 at the National Weather Center. The one-day conference is designed for insurance agents, adjusters, and citizens to learn more about Oklahoma's weather extremes and how that impacts the insurance industry.

"The Climate and Loss Mitigation Conference has increasingly become one of the most popular seminars for adjusters, agents, and citizens," said Commissioner Kim Holland. "Our State's pool of resources at the National Weather Center and our experience dealing with nearly every kind of weather- and climate-related incident imaginable allows us to put on an event where participants leave with knowledge and resources they couldn't acquire anywhere else."

Florida Insurance Commissioner Kevin McCarty will deliver the keynote address on the National Association of Insurance Commissioners' (NAIC) recently reformed national catastrophe plan. A panel featuring members of the media and National Weather Service will discuss effective communication in a weather crisis. Other presentations include the challenges of a changing climate, reducing risk to wildfire, tornadoes in Oklahoma, floodplain management, business continuity, and finding weather and climate information on the web.

The conference is open to the public at a cost of $19. The seminar also provides six hours of continuing education credit for licensed producers and adjusters for $39. Lunch is included in the registration fee for all attendees.

For additional information, please visit http://www.ok.gov/oid/Climate_Conference.html or call Jason Sutton at 405.522.4066.

The Oklahoma Climatological Survey (OCS) and the new Southern Climate Impacts Planning Program (SCIPP) will host the 7th annual Climate Prediction Applications Science (CPAS) Workshop March 24-27, 2009 in Norman, Oklahoma. This annual workshop brings together a diverse group of climate applications researchers, climate product developers, and users to discuss developments in research and applications related to climate services and the use of climate prediction in societal decision making. The meeting has four goals:

1. to identify new climate prediction applications research,
2. to "build community" by promoting interactions between integrated climate-sensitive research and service communities,
3. to assess impacts of climate forecasts on environmental-societal interactions,
4. to provide feedback to producers of climate products on user requirements.

Consistent with these goals, a variety of themes will be addressed at the 2009 workshop including the following: Stakeholder Evaluation of Climate Products and Services, Drought Monitoring and Tools, Water Issues, Agricultural Applications, Regional Climate Modeling Applications, Extreme Events and Severe Weather Applications, Products and Tools, and Fostering Collaborations in Decision Support Tool Development.

OCS and SCIPP were selected to host the 2009 CPAS Workshop following the selection of SCIPP as the ninth and newest Regional Integrated Sciences and Assessments (RISA) program in the United States in 2008. The National Weather Service Climate Services Division co-organizes the workshop each year with different partners who host the event.

For more information on SCIPP, which is a collaborative research program between the University of Oklahoma and Louisiana State University, please visit the new program website at: http://www.southernclimate.org. For more information on about this year's CPAS Workshop please visit: http://climate.ok.gov/cpasw/.

February 2009 will not be remembered for its warmth, even though it was the 10th warmest on record, nor for its dryness, with a less-impressive rank of 46th driest. Unfortunately, the month's claim to fame comes from the deadly tornado which struck Lone Grove on the 10th. The EF4 twister, February's first violent tornado since accurate statistics began in 1950, killed eight and injured 46 others. Another couple of tornadoes roared through the north part of Oklahoma City and Edmond. The Lone Grove tornado was the state's first killer tornado during the month of February since 1975, and the strongest since two F3 tornadoes struck in 1961. Six confirmed tornadoes struck the state on the 10th, tying it with 1975 for the most tornadoes during the month of February. Other than that which fell on the 10th, precipitation was almost non-existent. The February statistics helped the winter season to finish as the 16th driest and 33rd warmest on record.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

An exceedingly dry and relatively mild January was interrupted near its end by the most significant winter storm to date of the current season. The storm, which struck on January 26-27, brought travel across the state to a standstill as snow, sleet, and freezing rain made roads nearly impassable. Up to 3 inches of sleet fell in central Oklahoma, with another couple of inches of ice accumulating on power lines in the east. More than 50,000 utility customers were left without power at the peak of the storm. The damage increased significantly into Arkansas. Before that storm, the month was shaping to be one of the driest on record. With that added boost of precipitation, however, the rankings rose to the 26th driest January since 1895 with a deficit of around three-quarter inches. The month was also warmer than normal by about a degree, which still ranked it as the 56th coolest on record.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

With drought continuing to intensify across Oklahoma, the state received unwelcome news from the eastern equatorial pacific region: La Niña conditions have returned, and are expected by NOAA’s Climate Prediction Center (CPC) to continue through the first half of 2009. While these cooler-than-normal pacific waters may be thousands of miles away, climate studies have shown the phenomena can still impact the weather in Oklahoma.

La Niña influences weather across the world, but it influences Oklahoma’s weather by altering the jet stream’s path over the U.S., pushing it farther to the north. The Pacific Northwest would then see increased stormy conditions while the southern sections of the U.S., to the south of the altered storm track, would experience precipitation deficits. Warmer weather is also a possible implication for Oklahoma during La Niña conditions.

The combination of warmer and drier conditions for Oklahoma would not bode well for the upcoming fire season, which generally peaks in February and March. There are currently 18 counties with burn bans issued by local County Commissioners in Oklahoma. These burn bans coincide with the worst drought-stricken areas of the state.

Drought conditions in south central Oklahoma are currently labeled “severe” by the U.S. Drought Monitor, with “moderate” drought and abnormally dry conditions in other areas. Much of the southeastern half of the state has had 20-40 percent of normal precipitation over the last 120 days (mid-September through mid-January). In fact, the Oklahoma Mesonet sites at Burneyville and Ardmore have recorded a meager 2.1 inches of precipitation since September 16, 2008. Similar amounts are indicated by the Oklahoma Mesonet across southern and eastern Oklahoma.

CPC considers cooler-than-normal ocean temperatures in the equatorial pacific region La Niña “conditions” if they are forecasted to persist for three consecutive months. A full-fledged La Niña “episode” has not occurred unless those conditions exist for at least five consecutive overlapping three-month seasons. The last La Niña episode occurred from August 2007 through July 2008.

With a couple of weeks left to go, preliminary data from the Oklahoma Mesonet are painting the final picture of a wet and mild 2008 for Oklahoma. Bolstered by an extremely wet northeast corner, the statewide average precipitation total for Oklahoma stands at more than 36 inches, or about an inch above normal. This ranks the year as the 27th wettest since 1921. The statewide average temperature was 60.6 degrees, which is just a tad above normal.

Statewide extremes consist of a 110-degree temperature reading at Freedom on August 4. The state’s lowest recorded temperature of -4 degrees occurred at Boise City on January 17. The Oklahoma Mesonet site at Jay had the highest precipitation total at 66.52 inches. The lowest total of 12.5 inches was reported at Kenton in the far western Panhandle.

The statewide averages are made up of regional averages, of course, and they don’t adequately depict the variety of weather our state saw in 2008. Included in that above-normal statewide precipitation total is a devastating drought in the western Oklahoma Panhandle, which abated in late summer, and a burgeoning drought in south central Oklahoma. The northeast region was, on average, more than 12 inches above normal, while south central sections were nearly 8 inches below normal.

Preliminary data from the National Weather Service lists 77 tornadoes touching down in Oklahoma during 2008, compared to the 1950-2007 average of 53. Breaking those numbers down, 65 of those twisters were weak EF0-1 tornadoes, 10 were rated as EF2, and one each rated EF3 and EF4. Included in those numbers were a rare November tornado and an even rarer December tornado.

NORMAN, OK - Representatives from the University of Oklahoma and Oklahoma City came together at the National Weather Center this morning to unveil the Oklahoma City Micronet (OKCNET) – a 40-station network of real-time weather observing stations consisting of four Oklahoma Mesonet stations and 36 miniature weather stations mounted on traffic signals across Oklahoma City. The multipurpose network provides critical weather information for the daily operations of Oklahoma City, supports new scientific research focused on urban meteorology, and serves as a resource for the citizens of central Oklahoma.

OKCNET was developed during a 5-year collaboration between the Oklahoma Climatological Survey (OCS), the Oklahoma Mesonet, the University of Oklahoma (OU), and the City of Oklahoma City. The unveiling of the 40-station Oklahoma City Micronet represents a significant milestone in the history of weather data collection in metropolitan areas and is the first of its kind in the world in terms of data collection, quality, and availability to a variety of customers.

"The Micronet’s technology provides remarkable information that will benefit our residents in terms of public safety," said Oklahoma City Mayor Mick Cornett. "It will provide City crews with real time, detailed information about weather conditions Citywide so we can better anticipate everything from the location of freezing roads and flash flooding to the direction a fire might spread. In this type of partnership everyone wins."

"The University of Oklahoma is proud to have supported the development, deployment, and operation of the Oklahoma City Micronet," said Dr. Paul G. Risser, Chair of the University of Oklahoma Research Cabinet. "We see the state of the art atmospheric monitoring network in Oklahoma City not only as a valuable resource to the academic and research activities at the National Weather Center, but also as a tool that will pioneer new insights into urban meteorology and climate that will benefit anyone living in urban environments around the globe."

To learn more about OKCNET and view current weather data, visit the website at http://okc.mesonet.org.

Contacts:
Dr. Jeff Basara, Director of Research, Oklahoma Climatological Survey
Phone: 405-325-1760 E-mail: jbasara@ou.edu

Brad Illston, Research Associate, Oklahoma Climatological Survey
Phone: 405-325-5445 E-mail: illston@ou.edu

October was a cool month for most of the state, and thanks to another intrusion of tropical moisture from the pacific, wet for those of a western persuasion. The remnants of Hurricane Norbert soaked the northwestern one-third of Oklahoma and gave the Panhandle region its seventh wettest October on record. North central and west central Oklahoma were also benefactors of the tropical moisture, and their October totals ranked as the 13th and 11th wettest on record, respectively. On the other hand, the southeastern two-thirds of the state were parched with deficits of 2-4 inches of rain. On a statewide basis, the month ranked as the 48th wettest and 30th coolest on record. Severe weather was absent for the most part other than a few cases of strong winds and large hail. An early freeze visited the state on the 23rd when Kenton dropped to 24 degrees to go along with other sub-freezing temperatures across the southeast and far northwest. The year continued to come up a bit cool and ranked as the 48th coolest on record for the January-October time period. The same period ranked as the 21st wettest according to precipitation statistics.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

What is happening with our climate and weather? What are seasonal outlooks and why do they never seem to be right? What is real in the climate change debate? Are there better ways to manage drought? If you have asked any of these questions, then you should attend a one-day Climate Workshop this fall, compliments of the Oklahoma Climatological Survey (OCS). These workshops, offered at several locations around the state, will provide basic knowledge about our climate and weather, describe causes of climate variability and change, and help you find additional sources of information. The workshops build upon more than a decade of experience OCS has with public safety officials and K-12 teachers and students.

These workshops are geared toward providing more in-depth coverage than you can get with a brief one or two-hour presentation but do not require too much time away from your home or office. Specific topics include:

• Introduction to weather and climate - what shapes Oklahoma's climate and weather patterns?
• Climate change and climate variability - what might the future hold for us?
• Finding climate information - what products are out there and how do you use them?
• Climate hazards - what are the major weather-related threats in your town?
• Drought - what do we know about drought and how can we stay ahead of the next event?

In addition, there will be activities involving El Nino and tree rings to give you a hands-on understanding of what the climatologists do. We promise to do all we can to make climate fun!

The workshops are funded by a federal grant from the National Oceanic and Atmospheric Administration. As part of the grant, we will be conducting an evaluation of the effectiveness of these workshops. Your participation in the evaluation is completely voluntary but your feedback will help us to better identify strengths and weaknesses of the presentations and activities. We are also interested in finding out how you may use climate information in the future. If you agree, we will contact you several months after the workshop to request additional feedback. Of course, you can participate in the workshop without taking part in the evaluation activities.

This is your chance to not only learn about Oklahoma's climate, but to help shape the future of how climatologists inform - and learn from - others.

Workshop Locations
November 24 - Tulsa
December 1 - Ada
December 4 - Ardmore
December 8 - Weatherford
December 11 - Ponca City
December 15 - Norman

For further information about the workshops and registration materials, please contact Nicole Giuliano, Oklahoma Climatological Survey, nicole@mesonet.org, (405) 325-2541.

If you have questions about the evaluation, please contact Tom James, Institute for Public Affairs, University of Oklahoma, tjames@ou.edu, (405) 325-6622.

Please return the registration form to OCS.

The first big cold front of the season is coming through Oklahoma, right on cue. As temperatures behind the front fall into the 50s with nighttime lows in the 30s, parts of the state will see their first frost of the season, and perhaps their first freeze. Normally, most of the northern half of the state sees their first freezing temperatures on or around Halloween, just about a week away. In about 1 out of 10 years, most places in Oklahoma have already seen their first freeze, while there is about a 1 out of 10 chance for most places to make it to mid-November without a freeze.

The earliest freeze of the fall season? That occurred on September 15 in 1993 at Freedom and Hammon, and in 1947 at Kenton. The latest fall freeze occurred in 1998 as Lake Eufala, Okemah, and Ardmore made it until December 21 before recording their first 32-degree temperature.

So while freezing temperatures may not be in the forecast for the next couple of days, they are likely not far behind.

For more information on freeze dates in Oklahoma, visit http://climate.mesonet.org/ and look in the Normals & Extremes section.

A triple dose of tropical mayhem brought parts of Oklahoma more rain that it could handle for the first two weeks of September. The sogginess was immediately followed by an upper-level ridge of high pressure which rounded out the month with two weeks of absolutely gorgeous weather. The remnants of Hurricane Gustav struck during the first week of the month and brought heavy rains to far eastern Oklahoma. Gustav was but a precursor to the big event, however, as the twin tropical cyclones Lowell and Ike picked Oklahoma as a favored vacation destination on their downward spiral the following week. The rains of those first two weeks propelled the month to rank as the 43rd wettest September on record. The month was significantly cool as well and ranked as the 15th coolest on record. Severe weather was present during those early-month storms, although most reports were of flooding due to the heavy rains. A few cases of tennis ball size hail were reported with a few of the storms. There have been no confirmed tornado touchdowns since late May according to preliminary data from the NWS.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Heavy rains produced by dying tropical systems from both the Atlantic and Pacific oceans have nearly eradicated any trace of drought in Oklahoma over the last seven days. Remnants of Tropical Storm Lowell crossed western Oklahoma and merged with a cold front to inundate that part of the state while the remnants of Hurricane Ike struck eastern Oklahoma. The U.S. Drought Monitor now portrays the western two-thirds of the Panhandle as the lone section of the state currently experiencing excessive dryness. The rains, which largely fell between September 10 and September 14, totaled between 4-7 inches in the northwestern half of the state and 1-4 inches in the southeastern half, according to data from the Oklahoma Mesonet. Fairview recorded the most rainfall with 11.83 inches. That breaks the old record of 11.28 inches for September total rainfall in Fairview, set in 1936. Records for Fairview end in 1977, however, and begin in 1932.

The state is coming off of the 23rd wettest summer (12.53 inches of rainfall averaged statewide, 2.76 above normal) on record, and the 18th wettest August (4.38 inches statewide average, 1.61 inches above normal). For the year thus far, from January 1-September 17, the statewide average rainfall total of 32.31 inches ranks as the 9th wettest such period on record, more than 5 inches above normal. Northeastern Oklahoma is experiencing its wettest year-to-date on record with 48.39 inches, on average, nearly 18 inches above normal.

The Oklahoma panhandle continues to have drought conditions deemed "moderate" and "severe", a far cry from "exceptional" - the Drought Monitor's worst designation - label they had for most of the summer. For the year thus far, as of September 17, the Panhandle still has a deficit of nearly 4 inches to rank as the 21st driest such period on record.

We are all aware of the risks of hurricanes when they come ashore – high winds, storm surges, and occasional tornadoes. But sometimes hurricanes are at their most destructive well away from the coast, where you rarely see live media coverage. Inland flooding associated with the remnants of tropical systems have caused some of the most extreme flooding in Oklahoma's history. Such is the concern in Oklahoma during the next few days as the remnants of Pacific Hurricane Lowell and Atlantic Hurricane Ike are forecast to move into the Southern Plains region. Widespread flooding rainfall over much of Oklahoma is a possibility with these systems, according to the National Weather Service.

There have been some phenomenal one-day totals associated with the remnants of tropical systems in Oklahoma, such as the 15.68 inches that fell in Enid on October 11, 1973 from an isolated thunderstorm, but it has been the continuous rains over several days that have racked up the greatest totals.

More than 14 inches of rain over a 3-day period is needed just to make the Top-10 list of 3-day rainfall totals, according to archives from the Oklahoma Climatological Survey. The greatest 3-day total occurred between October 12th and 14th, 1981, when several locations reported more than 18 inches of rain in Marshall and Johnston counties.

So were these excessive totals caused by tropical storms? The answer is yes, but not the ones that may come to our minds. Although Atlantic hurricanes grab our attention, it is the remnants of Pacific Hurricanes that have wrecked the most havoc on our state. The October 1981 event was caused by Hurricane Norma, which went on to drop nearly 25 inches of rainfall in one week! Hurricane Paine came in second on the list. Of these Top-10 events, none were associated with tropical systems from the Atlantic Ocean.

You can learn more about how Pacific hurricanes have affected Oklahoma's weather in the Fall 2006 edition of Oklahoma Climate, http://climate.mesonet.org/seasonal_summary.html.

August was a wet month for most of the state as record-setting precipitation fell over parts of central and southern Oklahoma. Oklahoma City in particular set several precipitation records, including their All-time August rainfall total and all-time August daily rainfall total. Statewide, the wet weather propelled the month to the 18th wettest August on record. The rain and associated cloud cover helped the month finish as the 27th coolest August on record as well. The only area not enjoying the abundant moisture was north central Oklahoma which suffered its 25th driest August on record. Oklahoma City's official total of nearly 10 inches for the month breaks the old record for August rainfall set in 1906. Severe weather was sporadically reported. Large hail and high winds did occur, but flooding was the most frequent severe weather type. The year's high temperature of 110 degrees was reported at Freedom on the fourth. The highest rainfall total was recorded at Waurika, which came in with nearly 12 inches.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Prodigious rainfall amounts across Oklahoma have helped propel August to a top-three finish for precipitation. Even the Panhandle, which had been mired in severe drought conditions, helped push the total higher with their third-wettest August on record thus far. In fact, every region of the state has been decidedly on the wet side of normal for the month save for north central Oklahoma which has experienced a deficit of about an inch. The southwest and southeast corners of the state have each experienced their second-wettest August on record with surpluses of more than three inches.

The rains started in earnest on August 7 and have continued nearly uninterrupted through August 20. Some of the heavier amounts recorded by the Oklahoma Mesonet during this time include a 5.58-inch total from Shawnee on the 11th and totals of over six inches from Walters and Waurika on the 18th. The Oklahoma Mesonet site at Waurika recorded the most precipitation for the month with 11.7 inches. Blackwell recorded a paltry 0.5 inches over that same period.

July was fairly normal for these parts, both statistically and weather-wise. The month ended as the 53rd warmest and 47th driest out of the 114 years on record. The northern half of the state saw the most rain and accounted for the bulk of the near-normal total while the southeast went thirsty. Severe weather was thankfully sparse after a few months of tumultuous weather. Drought conditions lessened somewhat in the Oklahoma Panhandle with 2-4 inches of much-needed rainfall. Cimarron County, however, continued with conditions compared to the Dust Bowl days, according to long-time residents of the area.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Monday's excessive heat brought the statewide-averaged high temperature to 103.42, based on 120 Oklahoma Mesonet stations across the state. This value represented the warmest afternoon observed in Oklahoma since August 2006, and the 23rd-warmest day in the history of the Mesonet (14+ years since 1994). The Mesonet observation of 110 at Freedom was the highest temperature observed by the Mesonet since August 2003.

The Oklahoma Climatological Survey and the Oklahoma Mesonet will welcome 42 K-12 teachers to the EarthStorm Weather Workshop in Norman, OK on July 15-18, 2008. The EarthStorm Workshop will be held at the National Weather Center (NWC). Teachers will enjoy four days touring weather facilities and presentations from scientists and University of Oklahoma students. New teachers will begin learning basic meteorology concepts and use Oklahoma Mesonet data in classroom activities. Veteran EarthStorm teachers will join the us the second day.

Days 2-4 will cover thunderstorms from all sides. Speakers will explain weather ingredients that lead to severe events, explain storm structure and development and show video from actual storms. A case study will look back at the Greensburg, KS EF-5 tornado from 2007. Staff from the Norman National Weather Service Forecast Office will answer questions during an evening balloon launch. Afterwards, the teachers will view the Oklahoma Mesonet tower located in the parking lot (This tower is used for tour groups and is not part of the official data records of the Oklahoma Mesonet.).

Teachers will have the opportunity to learn about current and future radar technologies. They will visit the Phased Array Radar on north campus and get up close with a SMART-R radar (the ones mounted on the back of a truck). We will end our discussions on severe weather by looking back at the Union City Tornado of 1973 and Tropical Storm Erin from 2007.

Staff from the National Weather Center partner agencies and University of Oklahoma students will form two panels to discuss their high school, college and/or work experiences. The teachers will be able to ask questions about the skills need to earn a degree and how they can better help prepare their students for college.

We hope the teachers leave with an eagerness to share what they learned with their students and colleagues.

June was a very active weather month in Oklahoma with a large number of severe storm reports. Heavy rains in all but the extreme northwest and south meant a wet month as well – the 25th wettest June on record, in fact. The Oklahoma Panhandle continued without significant precipitation, still mired in severe drought conditions. The month also finished as the 32nd warmest June on record. There were 34 reported instances of hail at least two inches or greater during the month to go along with 23 instances of winds greater than 70 mph. Not to be outdone, there were 25 reports of flooding, most of which occurred in northeastern Oklahoma.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

A major return of significant tornadoes occurred in May. Seven twisters rated at least EF-2 in intensity touched down within the state's confines in addition to 24 of the weak variety. The most unfortunate statistic was the cost in lives, however, as a violent EF-4 tornado plowed through the small town of Picher on May 10th and claimed the souls of six Oklahomans. Another tornado struck and destroyed a hog farming operation near Lacey with the entire episode shown live from a local news helicopter. The preliminary count of 31 tornadoes was the most for any month since May 2003 when 59 tornadoes touched down. The six deaths were the most in a single day since the deadly May 3, 1999, Moore-South Oklahoma City EF-5 that killed 36. Severe weather was widespread throughout the month, especially in the form of large hail. Twenty-four instances of hail two inches or greater were reported to go along with the tornadoes. Oddly, despite all the tornadoes and severe weather the month's final rainfall tally finished below normal for much of the state. The statewide average rainfall was a tad below normal to rank as the 53rd driest since 1895. The month was fairly warm as well and ranked as the 49th warmest on record. The spring season ranked as the 20th wettest on record but a tad cool with the 51st-coolest ranking.

Full monthly summary available online at:
http://climate.mesonet.org/monthly_summary.html

Drought, flooding rains and severe weather were the big story during the past week - certainly not atypical May weather in Oklahoma. The tornadoes grab the headlines, of course, but another less-telegenic disaster continued to worsen in the Panhandle as the National Drought Mitigation Center upgraded the drought in that region from "severe" to "extreme." The drought conditions were worse in the western half of the Panhandle where precipitation totals since the beginning of the current water year - October 1, 2007 - dropped to less than 20 percent of normal.

The severe weather was highlighted by a series of tornadoes that struck northwest Oklahoma, the first in Harper County on the 23rd which damaged homes and outbuildings northeast of Fort Supply. Preliminary reports placed the tornado in the "significant" category, rated at least an EF-2 on the Enhanced Fujita Scale of tornado intensity. At least eight tornadoes touched down on the 24th in Kingfisher, Garfield and Noble Counties, but that count could increase after a closer look at damaged areas. That series of tornadoes was broadcast nationwide as local television reports were picked up by several cable news channels. One of the tornadoes wowed television audiences as it destroyed a hog farm near Lacey.

Large hail was another unwanted and frequent visitor during the period, from baseball size hail on the 22nd near Kingfisher to softball size hail in Roger Mills County on the 26th. The hail damaged wheat crops nearly ready for harvesting in northwestern, north central, and southwestern Oklahoma, and stripped the bark off of trees in Jackson County.

Precipitation associated with the thunderstorms was heavy in many areas, especially in north central Oklahoma where the Mesonet station at Red Rock recorded 5.6 inches of rainfall for the period. Four-to-five inch amounts were common across that area. Temperatures continued unseasonably warm across the state and combined with moisture from the Gulf of Mexico to make for uncomfortable afternoons. The state's highest temperature occurred at Altus on three separate days: the 23rd, 24th and 26th. In contrast, Hooker's high temperature reached a relatively chilly 67 degrees on the 27th. The state's lowest temperature of 44 degrees was recorded by the Mesonet site at Boise City on the 24th. On that same day, the minimum temperature at Clayton was 78 degrees.

The April 2008 Monthly Climate Summary is now online at: http://climate.mesonet.org/monthly_summary.html

Highlights:

• Same as it ever was...drought in the west and flooding in the east
• First significant tornadoes in the state since May 2007
• Microburst winds wreak havoc in Muldrow
• The 32nd coolest April since 1895

In the midst of another wet spring, why would the Oklahoma Climatological Survey post a story about drought? That's because portions of the Oklahoma Panhandle are in an extended dry period. This week, the Drought Monitor (http://www.drought.gov/) moved portions of Cimarron and Texas Counties up to D2 - Severe Drought.

While the year-to-date total for the state stands as the 13th wettest on record, the Panhandle and far northwestern Oklahoma have recorded their 11th driest January-April period on record. Boise City has recorded less than one inch of precipitation in the last 6 months. In fact, the meager total of 0.81 inch from November 2007 - April 2008 is their lowest accumulation on record by a wide margin. It has been 220 days since the Mesonet station at Boise City recorded one-quarter inch of precipitation from a single storm. The last time the area recorded significant precipitation was during the December 2006 blizzard

Worse news yet is that forecasters expect the drought to continue through the summer. As the region moves towards its rainy season, it will be important to keep a close eye on the weather and the impacts. We encourage you to tell us about how the drought is impacting you. Send a report in to the Drought Impact Reporter (also on the Drought Portal website, www.drought.gov), or e-mail us at ocs@ou.edu.

NORMAN--Through an international, competitive bidding process, the University of Oklahoma was recently selected by the Meteorological and Hydrological Service (DHMZ-Drzavni hidrometeoroloski zavod) of the Republic of Croatia to undertake a comprehensive modernization Feasibility Study for the DHMZ. Led by Regents Professor Ken Crawford, Director of the Oklahoma Climatological Survey, the study team consists of a diverse collection of meteorological experts from the National Weather Center. The team will evaluate the current monitoring equipment in place throughout Croatia and the forecasting techniques currently in use, and develop a plan to modernize all aspects of the country's monitoring, analysis, forecasting, and warning systems.

Adverse weather, flooding activity, and environmental hazards cost the Croatian economy approximately $218M annually, severely impacting the quality of life of its citizens and reducing economic development. The upcoming Feasibility Study will provide critical justification and evidence required to proceed forward with obtaining the necessary funding to implement a national upgrade and modernization of the DHMZ services. The project will include a series of in-country visits to all parts of Croatia and is expected to require approximately one year to complete. This feasibility study will be performed utilizing and harmonizing the outcomes of the Feasibility Study on the Strengthening of the Hydrometeorological Services in the South Eastern Europe completed by the Finish Meteorological Institute, Finish governmental organization VTT and the DHMZ under the umbrella of the World Meteorological Organization, World Bank and UNISDR.

"The selection of the University of Oklahoma to carry out this feasibility study is further evidence of the high international regard for the several University weather and climate programs involved," said John Snow, Dean of the College of Atmospheric and Geographic Sciences. Snow also noted that "we are excited about the possibilities this selection opens up for our programs to do similar studies throughout southeastern Europe."

This study has been organized through the recently established Office of Weather Programs and Projects at OU. A part of the Weather Sphere -- a collaborative partnership centered in Norman, Oklahoma, growing to become international leaders in weather and climate-related education and training, research and development, and operations and services -- OWPP specializes in the transfer of meteorological knowledge to applied meteorological projects both nationally and internationally.

Remarkable rainfall totals from the eastern half of the state propelled March to the sixth wettest since 1895. The southeastern corner averaged more than 12 inches of rain for the month to eclipse the established normal by more than eight inches, ranking as the wettest March on record for that part of the state. Rainfall tapered off towards the Panhandle, leaving that region in a cloud of dust where less than a quarter of an inch of rain fell on average. As for temperature, the month ended in the middle of the pack and ranked as the 43rd warmest on record. Three major storm systems provided most of the rain and a fair amount of severe weather as well. Officially, four tornadoes touched down during the month in addition to four others that were not yet confirmed. The worst of the tornadoes was an EF1 that struck Edmond and did significant residential property damage. Buffalo received hail the size of softballs early in the month, and extensive flooding occurred in eastern Oklahoma with each storm system. A significant snowstorm struck southeastern Oklahoma early in the month, dropping more than a foot of snow in LeFlore County. An even earlier snowstorm dropped nearly a half of a foot in the same general area.

Full monthly summary available online at: http://climate.mesonet.org/monthly_summary.html

The Oklahoma Climatological Survey is proud to announce the Winter 2007-2008 edition of its seasonal climate series "Oklahoma Climate," available online at: http://climate.mesonet.org/seasonal_summary.html.

Enjoy some stuffing with the following great stories:

• Is the December 2007 ice storm the worst in state history? We compare past events and let you decide.
• NEXRAD is the best radar system ever! Well, until now...learn about the new polarimetric radar in this issue.
• A new feature! Learn about luminaries of the Norman weather scene with our interview section.
• Climate change looms on the horizon. The Climate Survey weighs in on the issue with our official statement on climate change.
• Our friends at the National Weather Service look at last summer's brush with Tropical Storm Erin once again,this time focusing on the flooding.
• Our classroom exercise helps students understand ice storms and the damage they can inflict.
• Spring horticulture tips for lawn and garden enthusiasts.
• An agricultural summary of the fall months.
• A fall climate summary, including daily highlights.
• Winter weather myths are just as dangerous as severe weather myths. Stay safe by reading our own version of "Mythbusters"!

Beneficial rains fell over most of Oklahoma February 15-17 which helped to alleviate recent wildfire flare-ups. The moisture also delayed the progress of drought conditions which had once again begun to advance across the western and southern portions of our state. The moisture was even more welcome since it came mostly in the form of a very cold rain, as opposed to the freezing rain that was feared across the western half of the state. A few problems with electric power utilities developed late Friday night and into early Saturday morning, but warm air moved into the region from the south which helped melt accumulated ice from power lines and trees before the calamity of the December 2007 ice storm was relived.

Most of the state saw more than an inch of liquid precipitation with 94 of 118 Oklahoma Mesonet sites hitting that mark. The precipitation was more plentiful in west central, central, and southeastern Oklahoma, however, where amounts ranged from 2-3 inches in general. The Oklahoma Mesonet site at Talihina led the state with 3.40 inches.

Unfortunately, the western portions of the Oklahoma Panhandle remains parched. Drought conditions have continued to worsen in that area, which never saw the rains that most of the state enjoyed during the previous year.

The top-ten storm-total precipitation amounts from the Oklahoma Mesonet - February 15-17, 2008
Mesonet Site	Storm-Total Rainfall (inches)
Talihina	3.40
Clayton	3.27
Antlers	3.11
Oklahoma City North	2.79
Wister	2.60
Minco	2.58
Hugo	2.56
Weatherford	2.49
Bessie	2.41
El Reno	2.34

The 2007-08 winter thus far has seemed like a doozy. Maybe it was the gargantuan ice storm in December or the frigid temperatures we've seemingly been stuck in since Thanksgiving. When it comes to the weather, however, our memories are sometimes worse than reality. So, let's take a look at the statistics for this winter and see where we stack up on the miserably long-hard winter scale.

Since the beginning of the climatological winter on December 1, our statewide average temperature has actually been a bit warmer than normal by a few tenths of a degree. At least it's been wetter than normal, right? Sure, as long as you live in the Panhandle, which is experiencing its 15th wettest December 1-January 24 period on record. How about drier than normal then? Yep, but once again, as long as you live somewhere in the southern one-half of the state, or along the extreme western border. Southeastern Oklahoma, for instance, is having its 23rd driest winter on record thus far at more than an inch and a half below normal. Of course, some places in the dry area have been wet, and some places in the wet areas have been dry. That doesn't seem to make sense, but as most Oklahomans can attest, weather rarely does. All-in-all, the statewide average precipitation total for the winter is 2.65 inches - about a half of an inch below normal.

Our long-range forecasts are all pointing to drier and warmer weather for the next couple of months due to La Nina conditions in the equatorial pacific waters. So about all we can do is sit back and see what happens during the rest of this long-hard, strike that, fairly normal winter (save for a gargantuan ice storm, of course). And someday, today's kids can tell their children how they had to walk to school 10 miles in fairly normal weather.

December 1-January 24 Statewide Weather Statistics
Average High Temperature (F)	49.3
Average Low Temperature (F)	25.8
Average Temperature (F)	37.6
Average Rainfall	2.65

As we pass from 2007 to 2008 and the sound of chain saws and wood chippers diminish across Oklahoma, it provides an opportune time to reflect on the previous 365 days. The key to your 2007 weather experience in Oklahoma was undoubtedly WHERE you were during 2007 in Oklahoma. If you were in the Panhandle, the year was probably spent fighting pangs of jealousy towards central Oklahoma's abundant precipitation. If you were in central Oklahoma, you probably looked with envy at the dry weather of the Panhandle. And somewhere in between the droughts and floods, the truth is most Oklahomans enjoyed a very wet and somewhat warm year.

For the record, the statewide average precipitation total of 41.04 inches is about four inches above normal, making 2007 the 14th wettest year since records began in 1895. According to the Oklahoma Mesonet, rainfall totals across the state ranged from a high of 59.4 inches at the Red Rock in Noble County to a measly 12.0 inches at Goodwell in Texas County. Rankings-wise, the Panhandle experienced its 21st driest year on record while central Oklahoma enjoyed its wettest year on record (between floods, that is).

The year was warmer than normal, but not exceedingly so, ranking statewide as the 39th warmest since 1895, or about 0.3 degrees above normal. The Panhandle was the only region to finish below normal, yet it was still in the middle of the pack, ranked as the 52nd warmest on record.

2007 Oklahoma Mesonet Precipitation Statistics
Climate Division	Precip. (inches)	Departure from Normal	Rank since 1895	Wettest on Record	Driest on Record	2006
Panhandle	15.12"	-5.98"	15th driest	33.25 (1941)	9.50 (1910)	18.16
N. Central	37.67"	6.02"	10th wettest	45.52 (1957)	14.50 (1956)	19.84
Northeast	46.11"	4.14"	26th wettest	60.49 (1941)	21.84 (1963)	31.76
W. Central	36.69"	7.60"	7th wettest	43.04 (1997)	10.30 (1910)	23.31
Central	52.51"	14.52"	1st wettest	50.56 (1908)	16.10 (1910)	27.49
E. Central	46.25"	0.16"	41st wettest	67.06 (1973)	23.15 (1963)	39.00
Southwest	37.12"	6.32"	13th wettest	44.05 (1941)	11.96 (1910)	23.67
S. Central	42.53"	1.57"	27th wettest	57.51 (1957)	19.63 (1963)	30.93
Southeast	50.30"	-0.64"	47th wettest	71.98 (1990)	27.48 (1963)	46.98
Statewide	40.77"	4.08"	14th wettest	48.23 (1957)	19.04 (1910)	28.69

2007 Oklahoma Mesonet Temperature Statistics
Climate Division	Avg. Temp	Departure from Normal	Rank since 1895	Hottest on Record	Coldest on Record	2006
Panhandle	56.1°F	-0.3°F	52nd warmest	59.5 (1954)	53.3 (1912)	58.4
N. Central	58.7°F	0.2°F	48th warmest	62.2 (1954)	56.1 (1912)	61.1
Northeast	59.7°F	0.8°F	30th warmest	62.4 (1954)	56.2 (1917)	61.3
W. Central	59.2°F	0.4°F	44th warmest	62.4 (1954)	56.6 (1979)	61.9
Central	60.3°F	0.3°F	37th warmest	63.1 (1954)	57.3 (1912)	62.8
E. Central	60.9°F	0.6°F	34th warmest	63.4 (1954)	58.1 (1917)	62.8
Southwest	61.0°F	0.0°F	55th warmest	64.1 (1954)	58.8 (1906)	63.5
S. Central	62.0°F	0.1°F	50th warmest	64.7 (2006)	59.8 (1912)	64.7
Southeast	62.0°F	0.9°F	36th warmest	64.5 (1921)	58.9 (1979)	63.3
Statewide	59.9°F	0.3°F	39th warmest	62.8 (1954)	57.3 (1912)	62.2

The ice storm of December 8-10, 2007, is yet another in a list of significant icing events to hit the state since the turn of the millennium, and the second this year.  With estimates as high as 630,000 customers without power, it dwarfs the previous high of approximately 255,000 during the January 2002 ice storm. That fact begs the question:  "Was this ice storm more powerful than those of the previous decade?" That answer is difficult to ascertain. According to the sheer numbers of those left powerless, the answer would obviously be a resounding "yes".  As far as the amount of precipitation and ice accumulation goes, the amounts seem to be similar. So why is there such a discrepancy in the number of power outages? Location, location, location.

Keep in mind that the state's major metropolitan areas of Oklahoma City and Tulsa have largely received only glancing blows from the previous icing events. In fact, the I-44 corridor has seemed to act as a dividing line between the worst effects during past events. The December 2000 storm mainly affected areas south and east of I-44, while the January 2002 event devastated areas to the north and west of that interstate highway. It has always been well understood that should Oklahoma City or Tulsa receive the amount of ice as in the southeast or northwest during these previous events, the amount of structural and property damage would increase dramatically.

As for damage estimates, the tallies from previous storms soared into the hundreds of millions. Damage from the current storm will undoubtedly soar into that territory as well as clean-up begins and the impacts become more well-defined. The true cost of weather in Oklahoma is measured in lives, however, and the current storm has been particularly deadly. Twelve fatalities have been attributed to the inclement weather, all due to motor vehicle accidents.

Oklahoma Ice Storms Since 2000

• December 25-27, 2000: Major snow and ice storms struck statewide, especially powerful in southeast quarter. Power was lost to at least 120,000 homes and businesses, including 90 percent of the residents of McIntosh, Latimer, and Pittsburg counties. Extended power outages also led to disruptions of local water supplies in several areas. At least 27 fatalities were attributable to the extreme weather conditions, which extended well into January 2001. Total property damage in the state was approximately $170 million.
• January 28-30, 2002:  This powerful winter storm wreaked havoc on the northwestern half of the state, and none suffered more than the state's power suppliers.  The storm left over $100 million of damage in its wake, leaving some 255,000 residences and businesses without power.  A week after the icy system exited the state, 39,000 Oklahoma residents were still in the dark as utility companies worked around the clock to replace snapped poles and downed power lines.  Enid, a city of 47,000, was entirely without electricity for days.  Power companies estimated that power could be lost for up to two months in some rural areas of northwestern Oklahoma. Southwestern Oklahoma State University in Weatherford closed its doors for only the 4th time in its 100-year history.  The Oklahoma Association of Electric Cooperatives reported over 31,000 electrical poles destroyed due to the ice.  With about 20 poles per mile on an average electrical supply line, that results in over 1,550 miles of destroyed power supply capabilities, enough to stretch from Oklahoma City to New York City.  Electric power was not fully restored to all Oklahoma City residents until February 10, 11 days after the brunt of the ice storm exited the region.  Three weeks after the event, 2,320 customers remained without power. The most serious casualty in the wake of the ice storm, however, was the toll in human lives.  Seven fatalities were directly attributable to the effects of the late-January storm.  Four died in traffic accidents on the icy roadways, while two others died of asphyxiation while trying to get warm in enclosed spaces.  Another resident died when a large tree branch crushed him as he tried to clear his residence of debris.
• December 3, 2002:  The third significant ice storm in as many years, this icy blast left a damage footprint in a narrow band from west central to north central Oklahoma. Areas north of the icing region generally received 2-6 inches of snow, with some areas reporting more than eight inches. Moderate to heavy rainfall occurred to the south. The main impact of the ice storm was damage to electrical distribution systems. Because much of the area impacted by the storm is rural, the primary victims of the storms were members of rural electric cooperatives (RECs). About 30,000 REC customers were without power for some time during the storm. According to the Oklahoma Association of Electric Cooperatives, REC losses were about $4.5 million. Other power suppliers were impacted also. At the storm's peak, about 25,000 Oklahoma Gas & Electric (OG&E) customers lost power.
• January 12-15, 2007:  This storm caused catastrophic damage to the power systems in the eastern one-third Oklahoma, where ice accumulations were more than three inches in localized areas. Over 100,000 customers were without power at the height of this storm. One of the hardest hit areas was McAlester, where 15,000 lost power. Thirty-two deaths were linked to this storm:  19 perished in traffic accidents, eight succumbed to hypothermia, and three died due to accidental falls on the ice. Points northwest avoided catastrophic damage since most of the precipitation fell as snow and sleet.

The Oklahoma Climatological Survey is proud to announce the Fall 2007 edition of its seasonal climate series "Oklahoma Climate," available online at: http://climate.mesonet.org/seasonal_summary.html.

Enjoy some stuffing with the following great stories:

• A STRENGTHENING tropical system over Oklahoma? Yes, it occurred, and the Oklahoma Mesonet measured some astounding discoveries from the event.
• A hundred years of fall, a hundred years of glorious weather...interrupted by some really inclement weather at times.
• There is a mysterious globe hanging in the National Weather Center: UFO or teaching aid?
• That pesky jet stream gives us a secondary severe season in the fall.
• Our classroom exercise allows students to learn about evaporation and how to be better stewards of our fresh water supply.
• Winter horticulture tips for lawn and garden enthusiasts.
• An agricultural summary of the summer months.
• A summer climate summary, including daily highlights.
• Myths about flooding can be deadly. Stay safe by reading our own version of "Mythbusters"!
• Our photo section shows the glory of fall...with a bias towards football fans.

At one point this summer, 2007 looked poised to challenge 1957 as Oklahoma's wettest year on record. Bolstered by the wettest June since 1921, the statewide average rainfall through the end of July was more than eight inches above normal, and ranked as the third wettest such period on record. A strange thing happened as July faded on the calendar, however - the rains stopped. There were still deluges from time to time, of course. A rather indelible event will remain in Oklahoma's collective memory after a visit from an erstwhile Tropical Storm in September left 100-500 year rainfall amounts in west central and central Oklahoma. The flooding from that event was devastating, as were the rising waters of the spring and summer. Despite that dose of tropical moisture, Oklahoma returned to the dry pattern of the previous two years that saw drought ravage the state's winter wheat crop and diminish reservoir levels to some of their lowest on record. The August 1-November 20 period was the 22nd driest since 1921, about three inches below normal. The dryness varied across the state, but the southern tier of counties along with the Panhandle was hit the hardest, with drought designations from the National Drought Mitigation Center returning to the state for the first time since late March.

Central Oklahoma did manage to wrest away 1957's moniker as wettest year on record, however, with more than a month left in the year. As of November 20, Central Oklahoma had an average precipitation total of 49.60 inches for the year thus far, besting 1957's annual total of 49.14 inches.

Prospects for widespread precipitation look a tad underwhelming for the next few months. La Nina conditions have developed and strengthened in the equatorial waters of the south pacific, which could keep Oklahoma and the rest of the southern U.S. warm and dry though the winter months into early spring. An unfortunate consequence of the abundant rains of 2007 coupled with continued drying will be an increased risk of wildfires. Vegetation which grew at a rapid rate with the available moisture has now gone dormant and could act as a dangerous fuel source, should fires begin.

Overwhelming observational evidence indicates that the earth is warming, and that the cause of that warming is mostly anthropogenic (caused by humans) in nature. Further, the vast majority of scientists that actually study climate change believe that warming will continue for the foreseeable future.

Of course, climate change has become a highly contentious topic in public discourse, with the waters being muddied by extreme viewpoints and concerns. So where does the truth lie, and what are the implications for Oklahoma? The Oklahoma Climatological Survey (OCS) has been mandated by the Oklahoma legislature to provide climate information and expertise which could be of value to the public, as well as to state policy- and decision-makers. In that regard, OCS has conducted a review of current assessments of climate change research in order to craft a definitive statement on global climate change and the implications for Oklahoma - detrimental and beneficial alike. The statement is based purely on the findings of the vast majority of scientists that study climate change.

A round of strong to severe thunderstorms associated with a cold front pushed Oklahoma City's rainfall total for the year to 53.34 inches according to the National Weather Service, and established 2007 as Oklahoma City's wettest year on record. This breaks the old record of 52.03 inches set in 1908 with more than two months left in the year. Oklahoma City records date back to 1891.

According to data from the Oklahoma Mesonet, the year-to-date statewide average rainfall total of 37.44 inches through October 15 ranks as the 6th wettest since 1921 at more than seven inches above normal. That is still well behind 1957's total of 42.66 inches for the same period. The Oklahoma Mesonet site at Minco has recorded 54.20 inches of rainfall since the beginning of the year to lead the state.

Central Oklahoma sits at more than 17 inches above normal for the January 1-October 15 period with an average total of 47.94 inches. That puts the central region at just about an inch behind its record annual total of 50.56 inches set in 1908.

The September 2007 Monthly Climate Summary is now online at: http://climate.ocs.ou.edu/monthly_summary.html.

Highlights:

• Another month, more flooding...but it's getting better.
• The state was actually a bit dry as a whole. And warm, which should surprise nobody.
• A Mesonet station recorded a low of 39 degrees!
• A severe-weather injury occurred. Tornado? No. Flood? No. That leaves hail.

The Oklahoma Climatological Survey is proud to announce the Summer 2007 edition of its seasonal climate series "Oklahoma Climate," available online at: http://climate.mesonet.org/seasonal_summary.html.

Enjoy these stories on a rainy day:

• 100 years of summer in one magazine? Impossible...not!
• Drought killed the 2006 wheat harvest. This year's rain had to help, right? Think again.
• Squall lines are a major source of Oklahoma's annual rainfall total. We present an AWESOME climatology inside.
• Do you open up all your windows when a tornado approaches? Well, don't. Read about other weather myths in this issue.
• Our classroom exercise over soil moisture lets students get their hands muddy.
• Fall horticulture tips for lawn and garden enthusiasts.
• An agricultural summary of the spring months.
• A spring climate summary, including daily highlights.
• Stay safe in the wilderness with our camping safety tips!
• Check out some photos of the terrible flooding across our state the past few months, taken by OCS employees.

It's just not supposed to work that way. Tropical storms are not supposed to reform over land. Then again, with all the rain earlier this year, maybe it thought Oklahoma was the ocean. In what is about as rare of a weather event as anyone will ever witness, Tropical Storm Erin reformed over southwestern and central Oklahoma during the late afternoon and overnight August 18-19.

Shortly after 5 pm on Saturday, the remnants of Erin, which had been downgraded to a tropical depression, started to show signs of new life. Two brief tornadoes were reported in western Oklahoma, near Cordell. As the evening progressed, the storm continued to wrap up, bringing torrential rainfall across southwestern Oklahoma and slowly spreading eastward and northward across the state. Beginning at 1:15 am on the 19th the Mesonet (http://www.mesonet.org) site at Watonga, near the center of the circulation, reported severe winds nearly continuously for two hours. During this time, sustained wind speeds over 40 miles per hour were reported. Had that occurred over open water, Erin would have been upgraded to a tropical storm. Wind gusts over 70 miles per hour were recorded at the Watonga and Fort Cobb Mesonet sites, and the Watonga Airport topped the list with an 82 mph gust.

Erin continued to wrap up during the overnight hours, eventually forming a new eye, centered just north of El Reno at about 5 am. The circulation persisted for several hours, driving bands of moisture counter-clockwise around the eye. The slow-moving system dropped more than five inches of rainfall along its path, with over an inch common in a larger area from Erin's outer 'bands'. Of the Mesonet sites, Fort Cobb picked up the highest total - 9.24 inches. However, a CoCoRaHS (http://www.cocorahs.org) observer reported 11.00 inches northwest of Geary, noting "the amount was MORE than 11 inches. When I went out to check the gauge this morning, it was full, had clearly overflowed during the night, and I spilled some of the contents getting the gauge off the post. The majority of the rain occurred between 11 pm and 4 am."

Oklahoma has a long list of natural hazards we face year-in and year-out. Now it looks like we can add tropical storms to the list. It will be interesting to see whether our sure-to-be disaster declaration will be labeled as such, or get lost amongst the many other "severe storms and flooding" events in our history.

The rainfall added by Erin was yet another blow to an already water-slogged state, especially for central Oklahoma. Rainfall totals averaged over the central Oklahoma region stands at 43.14 inches since the beginning of the year, 19.09 inches above normal - easily the wettest on record for the area. The previous mark was set in 1957 with a January 1-August 20 total of 36.90 inches. Statewide, the year thus far is the 4th wettest on record with 31.96 inches, 8.42 inches above normal.

The summer season through August 20 is the wettest on record statewide with a total of 15.46 inches, 6.71 inches above normal. Central Oklahoma is 14.45 inches above normal for the June 1-August 20 period with 23.23 inches of rainfall.

To watch Tropical Storm Erin as it moved across Oklahoma, download WeatherScope from our Software (http://climate.ok.gov/software/) website and then click here

Mother Nature launched a dastardly and unprovoked attack on our cool summer, and now she has set her sights on our wet summer as well. Prior to August 5, the 119 Oklahoma Mesonet sites had recorded triple-digit temperatures three times. In the 10 days between August 5 and August 14, however, those same sites have recorded temperatures of at least 100 degrees 390 times. The statewide average temperature for August 1-14 was 82.0 degrees, 1.4 degrees above normal. The statewide average high temperature, which has been creeping up daily, was 96.1 degrees for the same time period. Nighttime temperatures have been inching downward as the state begins to dry out and the length of daylight hours decreases. Through those 14 days, the average nighttime temperature was 2.1 degrees above normal. Temperatures normally reach a high of around 94 degrees in mid-August, decreasing steadily to around 90 degrees at the beginning of September. The highest temperature in the state thus far has been 106 degrees recorded at the Hooker and Webbers Falls Mesonet sites on August 12 and 13, respectively. That's a far cry from the summer's coolest high temperature of 67 degrees, recorded at Boise City way back on June 14. It could be worse; for the same period in 2006, the Mesonet had recorded triple-digit temperatures 1079 times, with a high of 109 degrees twice.

Since the 100-degree temperatures ramped up in earnest on August 5, Oklahoma has recorded a measly 0.05 inches of rainfall on average statewide. In fact, as of the morning of August 15, the statewide average precipitation for the month thus far was 0.30 inches, more than an inch below normal and the 8th driest such period since 1921. Most of that rainfall occurred at a few locations. Slapout received 3.2 inches during that period while Byars had three inches. Nearly 50 of the Oklahoma Mesonet's 119 stations recorded no rainfall during those 15 days. The statewide average for the 30-day period from July 16-August 14 was 1.05 inches, which is the 10th driest such period on record. That is contrasted with the 60-day period from June 16-August 14, where the statewide average was 10.49 inches, more than four inches above normal and the 5th wettest on record.

Oklahoma's flirtation with a Canadian-style summer came to a crashing halt as triple-digit temperatures replaced the flooding rains of June and July. The main culprit in the journey back to normalcy is an upper-level ridge of high pressure that has become entrenched over the Southern Plains. The ridge has effectively stifled the widespread rains that the state saw for much of the summer and at the same time allowed temperatures to soar into the 100s with increasing frequency. Prior to August, the Oklahoma Mesonet's 117 observing stations had recorded only three 100-degree temperatures, the highest of which was 103 degrees at Goodwell on July 8. Those same 117 stations have recorded temperatures of more than 100 degrees 37 times between August 5 and August 8. Most of those extreme temperatures have occurred in extreme western Oklahoma and the Panhandle, which have been drier than points east. The highest temperature in the state, through August 8, has been 105 degrees at Buffalo, reported both on August 7 and August 8.

The upper-level ridge made the return to of Oklahoma's normal summertime weather an inevitability - heat, heat and more heat. The abundant precipitation of the previous two months have helped keep air temperatures down somewhat as the sun's rays work primarily to evaporate moisture from the surface. As the surface begins to dry, however, and vegetation loses its greenness, more of the sun's energy will be used to heat the ground. The heat that western Oklahoma has been seeing will begin to creep eastward, spreading eastward across the state.

Unfortunately, as the moisture from the ground is evaporated, it increases the humidity of the air near the surface. This adds to Oklahoma's normal hot and humid August conditions. Heat indices have been in the 105-110 degree range across portions of northern Oklahoma, prompting excessive heat warning and heat advisories from the National Weather Service.

A current heat index map from the Oklahoma Mesonet can be found at: http://www.mesonet.org/data/public/mesonet/maps/realtime/current.heat.gif

Incredibly, only three triple-digit temperatures have been recorded by the Oklahoma Mesonet's 119 observing sites during 2007. Of the nearly 12,000 high temperature observations reported by the network, the lone 100-degree readings were: 103 degrees at Goodwell on July 8; 101 degrees at Hooker, also on July 8; 100 degrees at Tipton on June 19. Results from previous years indicate that 2004 had the next-lowest total through July with 117 reports of triple-digit temperatures from the Mesonet. The highest total of 2520 came during the drought-induced heat of 1998. Last year's total through July was 1565.

Oklahoma's cool and wet summer continued through July according to preliminary data from the Oklahoma Mesonet. The statewide average temperature for the month was three degrees below normal to rank as the 11th coolest July since 1895. Cool summer months are normally associated with above normal precipitation and that was exactly the case this July as well. The statewide average rainfall totaled nearly four inches, more than an inch above normal, to rank as the 24th wettest July on record. The greatest area of surplus precipitation occurred from the southeastern tip of the state up through central Oklahoma. The southeast led the state with an average of more than eight inches, nearly five inches above normal - the 4th wettest July for that area.

This year's June-July period ranks as the wettest on record for the state with a surplus of more than six inches. Central Oklahoma led the state with a surplus of more than 11 inches. The Panhandle, on the other hand, was more than an inch below normal and experienced its 23rd driest June-July on record. Central Oklahoma had its wettest January-July on record with a total of 38.52 inches, nearly 16 inches above normal. Statewide, the June-July period ranks as the 13th coolest on record, more than two degrees below normal. The year thus far ranks as the 53rd coolest.

July 2007 Mesonet Statistics
Climate Division	Avg Temp	Departure	Rank	Rainfall	Departure	Rank
Panhandle	77.7	-1.9	32nd Coolest	1.67	-0.85	31st Driest
North Central	78.9	-3.3	12th Coolest	3.10	0.12	52nd Wettest
Northeast	78.9	-2.0	28th Coolest	3.05	-0.11	57th Driest
West Central	78.1	-3.6	8th Coolest	2.39	0.26	49th Wettest
Central	79.1	-2.9	19th Coolest	5.69	3.12	10th Wettest
East Central	78.6	-2.7	18th Coolest	5.12	2.14	23rd Wettest
Southwest	79.3	-3.9	7th Coolest	1.93	-0.25	53rd Driest
South Central	79.0	-3.7	7th Coolest	4.79	2.25	14th Wettest
Southeast	78.1	-2.8	8th Coolest	8.40	4.82	4th Wettest
Statewide	78.7	-2.9	11th Coolest	4.03	1.29	24th Wettest

How wet is it? Or is the real question "how dry was it?" Comparing the drought of the previous two years to the flooding rainfall of 2007 is indeed like comparing apples and oranges, with one notable exception - both hazards have been disastrous for those affected. The 2006 wheat crop was decimated by drought while the 2007 crop languished in fields too wet for machinery. The drought conditions of 2005 and 2006 spawned destructive wildfires while the torrential rains of this year have flooded homes and businesses across the state. The most unfortunate similarity is the cost in lives, however, whether it be those who were lost fighting wildfires or to the rising floodwaters. With those similarities noted, the statistics between the two periods could not be more striking.

According to data from the Oklahoma Mesonet, the statewide average rainfall through July 16 has already eclipsed the yearly rainfall amounts of both 2005 and 2006. The statewide average rainfall for the year thus far, through July 16, is 29.05 inches. The yearly totals for 2005 and 2006 were 26.93 inches and 28.59 inches, respectively.

The regional averages are even more outlandish. Central Oklahoma currently leads the state with an average of 37.76 inches - the wettest on record for that part of the state, 16.65 inches above normal. Compare that with identical periods from 2005 and 2006 when the averages were just 16.85 inches and 14.13 inches, respectively.

As a final exclamation point, consider the rainfall statistics from the Oklahoma Mesonet site at Minco, which has recorded 44.00 inches of precipitation through July 16. The same periods from 2005 and 2006 combined added up to 23 inches, a little more than half of this year's total. In fact, to match this year's total, you have to go back all the way to February 24, 2005 - that's February 24, 2005, through December 31, 2006. In other words, it took the rainfall from the previous 676 days at Minco to match this year's total accumulated in 197 days.

Oklahoma City might be considering changing its name to Seattle, given how much rain we've had recently. Friday morning's rains mark 17 consecutive days of rainfall in Oklahoma City, according to the National Weather Service. This breaks the previous record of 14 consecutive days, from May 29 through June 11, 1937. Although, if we went farther back in history, we hear the real record is 40 days (and nights)! Then again, maybe we're just trying to convince the Seattle Supersonics basketball team to move to Oklahoma City.

Since the most recent rounds of rainfall began in Oklahoma on May 24, the state has tallied 9.42 inches of rain (through June 27), on average, which is more than four inches above normal for the period. Central Oklahoma leads the way with an average of 13.38 inches. Now anybody who deals with Oklahoma weather knows that things are rarely average - some places get more and some get less. The "more" side of it totals as much as 19.72 inches at Minco and more than 18 inches at Marena, Medicine Park, Apache, Chickasha and Kingfisher.

All this rain makes it kind of hard to remember how dry it had been. When you figure the rain total for the last 365 days, it comes up just a bit above average. Southwest, west central, and central Oklahoma come up on the wet side and southeast comes up a bit below normal, with the state overall showing a surplus of 3.94 inches. The recipe? Take about 6 really dry months, about 3-4 near-normal months, and a couple of incredibly wet months and you have "normal," just like you would expect in Oklahoma!

Track your rainfall at http://climate.mesonet.org/rainfall_update.html

After two years of severe drought, Mother Nature turned the spigots on in relief but seems to have forgotten to shut them off. Consequently, flooding has become the hazard of choice during the past three months. Oklahoma's statewide average precipitation total for the year thus far ranks as the 19th wettest since 1921, 1.40 inches above normal. Much of that bounty is buoyed by the northwestern half of the state. The north central, central and west central regions are all experiencing year-to-date totals ranked within the top-ten wettest. The last 90 days have been particularly wet, with the state enjoying its 13th wettest such period. West central, central, and north central totals are all ranked in the top-six wettest during that same time frame. Not all areas of the state are sharing in the moisture surplus, however. The eastern third of the state has continued to dry out over similar periods. The southeast and east central sections of the state are nearly three inches below normal since the beginning of the year to rank as the 26th- and 29th-driest on record, respectively. The two-year precipitation statistics reflect the just-broken drought with virtually the entire state, save for the west central section, showing precipitation deficits. May 2005-May 2007 for southeastern Oklahoma is the driest such period on record.

It's somewhat standard for Oklahoma's severe drought episodes to end with a deluge instead of a trickle. The state's most notable droughts, the 1930s Dust Bowl and the 1950s, were both broken in a spectacularly wet fashion. The Dust Bowl episode was whittled away in early 1941 before being blasted from existence by a statewide average rainfall of 11.32 inches in October, the wettest Oklahoma month on record. The 1952-57 drought, considered the state's worst statistically, ended rather abruptly in May 1957 with heavy rains and major flooding on the state's largest river systems. That year still stands as the wettest in Oklahoma history at 48.21 inches.

The Oklahoma Climatological Survey is proud to announce the Spring 2007 edition of its seasonal climate series "Oklahoma Climate," available online at: http://climate.mesonet.org/seasonal_summary.html.

Enjoy these stories on a rainy day:

• In Oklahoma's centennial year, we celebrate 100 years of Oklahoma spring.
• There's a new Fujita Scale in town. Twist when you say that, stranger!
• Our classroom exercise exposes students to a tornadoes lesser-valued cousin...the straight-line severe wind.
• Oklahoma Mesonet sites move to the big city.
• Does our friend El Nino give us more tornadoes? How about La Nina? Find out in this issue.
• Our photo section showcases a different "EF" scale...the "ef"florescence of Oklahoma.
• Learn how to program your weather radio to avoid all those pesky warnings from several counties away.
• Summer horticulture tips for lawn and garden enthusiasts.
• An agricultural summary of the winter months.
• A winter climate summary, including daily highlights.

Governor Brad Henry proclaimed May as Flood Awareness Month, and apparently not a day too soon. In just the first eight days of May 2007, Oklahoma posted a statewide-averaged rainfall total of 3.53 inches. By comparison, May 2006 only recorded 3.03 inches - for the entire month. The normal May rainfall is 5.21 inches. In short, it took only eight days to surpass the total from the drought-plagued month of May 2006.

This rain comes on the heels of a wet April, which helped Oklahoma erase the last vestiges of a 2-year-long drought. On April 3, the U.S. Drought Monitor ended drought designations, although lingering effects still remained in pastures and reservoirs. With the May rainfall, the reservoir issue has nearly been resolved. Lake Thunderbird near Norman, which just a few weeks ago was nearly 30% below it's normal conservation level, is now nearly full. Lake Altus-Lugert, which had been less than half-full, is three-quarters full, great news for cotton-growers in southwest Oklahoma that rely upon the irrigation lake in the summer.

If there was any doubt about the recovery from drought in Oklahoma, this past week has put that to rest. Soil moisture at nearly every Mesonet site is saturated, the Keetch-Byrum Drought Index is virtually zero statewide and wildfire potential is almost non-existent. In the last 30 days, the driest part of the state (the Panhandle) has 114% of normal rainfall. Statewide rainfall totals place Oklahoma as the 7th wettest on record over the past 30 and 60 days and the 13th wettest year-to-date (through May 8). Even more incredible, every region of the state except the northeast is at or above normal for the water year (beginning October 1), and the northeast missed by only 0.03 inch. Oklahoma has not experienced a Spring like this since 1999.

As so often occurs in Oklahoma, we switched from one hazard to another. Instead of fighting wildfires, Oklahomans must now remember safety rules for floods. According to the National Weather Service, "each year, more deaths occur due to flooding than from any other thunderstorm related hazard. Why? The main reason is people underestimate the force and power of water. Many of the deaths occur in automobiles as they are swept downstream. Of these drownings, many are preventable, but too many people continue to drive around the barriers that warn you the road is flooded. Whether you are driving or walking, if you come to a flooded road, Turn Around Don't Drown. You will not know the depth of the water nor will you know the condition of the road under the water."

Earlier, Governor Henry proclaimed March as "Flood Insurance Month," part of a state campaign to spread the word about the availability of affordable flood insurance through the Federal Emergency Management Agency's National Flood Insurance Program (NFIP). According to the Oklahoma Water Resources Board, Oklahoma currently boasts 376 NFIP member communities, which consist of municipalities, counties, and tribes. Gavin Brady, State Floodplain Manager, notes that "implementation of sound floodplain management and building strategies, particularly through the NFIP, is the most effective way for communities to avert potential flood damages." However, he encourages communities to go "above and beyond" minimum NFIP standards, consistent with the national Association of State Floodplain Manager's ongoing 'No Adverse Impact' initiative. Brady points out that 87% of homes in Oklahoma's designated floodplains have no flood insurance.

As we continue to monitor rainfall patterns, we should pause and realize how vulnerable we remain to the effects of water, both too little last year and too much now. Water management is a critical issue for Oklahoma, both in managing excess to limit damages and preserving sufficient resources for the dry times. Climate change scenarios suggest that this will only get worse in coming decades. All Oklahoma citizens are encouraged to participate through local community planning and through the state's Comprehensive Water Plan process, to assure that we will become less vulnerable to these risks in the future.

Ashton Robinson Cook: Storm Prediction Center SCEP student

Spring can be the most violent season for Oklahoma weather. With spring in full swing, Oklahomans may be wondering about the prospects of the upcoming tornado season and whether El Niño or La Niña can increase or decrease probabilities of a tornado in an area.

El Niño and La Niña are part of a more complex climate system termed El Niño Southern Oscillation (ENSO). This climate phenomenon is driven by abnormal sea surface temperatures in the equatorial Pacific, with shifts in weather around the entire world attributed to ENSO. El Niño is the warm phase of this climate phenomenon, denoted by abnormally warm sea surface temperatures. La Niña is the opposite; it involves significantly cooler than average sea surface temperatures in the region. The third ENSO phase, Neutral, indicates sea surface temperatures that are near the climatologically normal level.

ENSO has its most pronounced effects on U.S. weather during the winter months. In a winter El Niño, warming of the equatorial sea surface temperatures forces a stronger than average subtropical jet to develop across the southern tier of the U.S. The jet tends to bring cooler, wetter conditions to the southern tier of states, including Oklahoma. In contrast, winter La Niña conditions tend to diminish the presence of the subtropical jet and displace it farther to the north. Generally, this results in drier, warmer conditions in Oklahoma. Although the effects are less clear during the spring months, cooler and wetter conditions generally prevail throughout the spring in El Niño months, with drier conditions noted during La Nina and Neutral months.

So are there similar shifts noted in spring tornado activity?

There is very little evidence that ENSO is responsible for shifts in spring tornado activity in Oklahoma. A brief analysis of tornadoes occurring in Oklahoma during spring and early summer (April, May, and June) between 1950 and 2005 reveals only very small shifts in tornadic activity across the state. Figures 1 and 2 indicate that some of the tornadoes during the La Nina phase seem to have longer tracks compared to tornadoes in El Niño phase events, especially across central and northern Oklahoma. Although the shift is evident, it is not very pronounced. Tornadoes occur in all parts of the state regardless of ENSO phase. In addition, it is difficult to determine a solid meteorological basis for this shift as distinct shifts in weather patterns (such as the climatological positions of jet streams, fronts, and drylines) during the spring months have not been determined.

A further analysis reveals that stronger tornadoes (rated F2 or higher in the Fujita Scale) occur slightly more frequently in the La Niña phase of ENSO (30.9%) compared to the El Niño phase (21.6%). While strong tornadoes are also a more frequent occurrence in Neutral phases (29.6%), it is difficult to draw valuable comparisons between Neutral ENSO phases and others because the Neutral phase occurs nearly twice as often (28 spring seasons) as both El Niño (13 spring seasons) and La Niña phases (15 spring seasons). As expected, the Neutral phase contains nearly double the tornadoes (1015) that either the La Niña (525) or El Niño phase (547) contains, indicating that the frequency of tornadoes across Oklahoma is not affected by ENSO phase.

In short, it appears that the effect of ENSO on spring Oklahoma tornado activity is minimal. The entire state has equal chances of experiencing tornadoes regardless of the ENSO phase. While stronger tornadoes occur less frequently in the El Niño phase compared to other phases, strong and even violent tornadoes (rated F4 or F5) have been observed in all three phases.

Sources:

The Oklahoma Mesonet is participating in the annual FFA state convention at the Cox Convention Center in Oklahoma City, April 24-25. Oklahoma FFA assists students interested in careers in more than 300 areas, ranging from agri-science to biotechnology to turfgrass management. The convention attracts thousands of students from all counties in the state. One stop in the exhibit hall is the Oklahoma Mesonet booth, where Al Sutherland and Laura McKay will be demonstrating how weather information is harnessed to help the state's agricultural industry deal with Oklahoma's weather.

Weather is no longer something that farmers and ranchers passively accept. Through technological advancements, they are now able to continuously monitor weather conditions on the local level and apply it to their practices. Results include increased production, reduced pesticide and fertilizer costs, and environmentally-friendly practices. One of the tools they use is the Mesonet's AgWeather page, http://agweather.mesonet.org/. AgWeather combines real-time information from the Oklahoma Mesonet with a variety of agricultural application models, market information, and Oklahoma State University Extension fact sheets to provide a comprehensive source of information for all varieties of businesses. We invite you to visit with Al and Laura at the booth, or to stop by the AgWeather website.

Oklahoma faces a wide variety of natural hazards. One of these, heat stress, will be highlighted in two events this week.

On Tuesday, April 17, the "Never Leave Your Child Alone" news conference will focus on heat deaths resulting from leaving children unattended in automobiles. The Oklahoma City Fire Department, Safe Kids Worldwide, and General Motors are teaming up on an information campaign this summer to draw attention to what is an easily presentable cause of death. Since 1998, at least 11 Oklahoma children have died from heat stroke when left unattended in closed vehicles, some for as short as only a few minutes. Even when the temperature is as low as 70 degrees, the temperature inside a vehicle can rise 19 degrees in just 10 minutes. Children are especially vulnerable, because their body temperatures rise at a rate of three to five times faster than an adult's. The news conference will occur at 3 p.m. at the Oklahoma City Police/Fire Training Center, 800 N. Portland. For further information, contact Tony Young with the Oklahoma City Fire Department, (405) 297-3314.

On Wednesday, April 18, hazards will be the topic of a day-long conference held at the National Weather Center. The second "Climate & Loss Mitigation Conference", hosted by the Oklahoma Insurance Department, will feature speakers and breakout sessions focusing on climate-related hazards, how those might change because of global warming, what impacts this might have on the insurance industry, and things we can do in our communities to make ourselves less vulnerable to both projected hazards and the hazards we already face. Registration is as low as $15 for seniors and students or $30 for the general public, and includes lunch. The conference is co-sponsored by the Oklahoma Climatological Survey, State Farm Insurance, and American Farmers and Ranchers Insurance. Additional information is posted at http://www.oid.state.ok.us/ or call (405) 325-2541.
Return of Deadly Tornado Ends Record Absence
March 29, 2007

The two confirmed tornado deaths on March 28 near the small town of Elmwood in Beaver County are the first in the state since April 11, 2001, according to statistics from NOAA's National Climatic Data Center. The nearly six-year span of 2178 days is the longest interval between killer tornadoes since accurate statistics began in 1950 and eclipses the previous record of 1457 days, which occurred between May 7, 1995, and May 3, 1999. The fatalities mark the first official tornado deaths in Beaver County, although additional records list a fatality near Balko in Beaver County on May 20, 1949. Beaver County's last tornado occurred on September 21, 2006 near Turpin.

Oklahoma's last tornado fatality occurred four miles east of Coalgate in Coal County a little after 4:30 pm on April 21, 2001, after a mobile home was thrown 200 yards and disintegrated, killing one. Oklahoma's 3028 tornadoes since 1950 have resulted in 265 deaths, over 4000 injuries and more than $3 billion in damage. The state's 27 tornadoes during each of the last two years are little more than half the annual average of 53.

Heavy rainfall in the northern one-third of the state has helped ease severe drought conditions in north central Oklahoma. The Oklahoma Mesonet site at Foraker recorded 5.31 inches of rainfall during the event, with 5.14 inches of that total occurring on the 20th. General amounts between 3-5 inches fell in Grant, Kay, Noble, and Osage Counties. Unofficial reports and radar estimates of 6-7 inches came in from the Newkirk and Red Rock areas. Flash flood warnings were issued by the National Weather Service for Kay and Noble Counties due to the heavy rains. Roads in and around Blackwell, Newkirk and Ponca City were reported under water on the 20th.

Much of north central Oklahoma remains in severe drought conditions according to the National Drought Monitor. The rest of the western half of the state is categorized as abnormally dry or in moderate drought conditions.

The Oklahoma Climatological Survey is conducting a workshop for public safety officials. The Spring Full Certification Course is March 13-16, 2007 at the National Weather Center in Norman. Completion of this course will deem the student as a Full Participant in OCS's OK-First program.
Grand Prize Winner
February 16, 2007

Dr. Matthew Haugland and Dr. Ken Crawford met with the Governor Brad Henry and Lieutenant Governor Jari Askins at the Oklahoma State Capital to honor Dr. Haugland for winning the Grand Prize at the National Collegiate Inventors Competition. The National Collegiate Inventors Competition recognizes and rewards innovations, discoveries and research by college and university students and their faculty advisers. Haugland's entry, titled "The Uncoupled Surface Layer Model," is based on his research of weather observations in microclimates. The Grand Prize carries a monetary value of $25,000 which Dr. Haugland intends to use to start his own private company based in Oklahoma.

The Oklahoma Climatological Survey is proud to announce the Winter 2006-07 edition of its seasonal climate series "Oklahoma Climate," available online at: http://climate.mesonet.org/seasonal_summary.html.

Thaw out with these stories:

• In Oklahoma's centennial year, we celebrate 100 years of Oklahoma winters.
• NOAA weather radios are being distributed to schools around the state to keep your kids safe.
• A recap of the National Weather Festival, held at the new National Weather Center.
• Our classroom exercise exposes a little-known but very valuable variable: the wet-bulb temperature.
• Bringing drought monitoring into the 21st century.
• Our photo section showcases the adorable kids of OCS employees enjoying this year's Winter Wonderland.
• Home heating tips -- protect your family while staying warm.
• Spring horticulture tips for lawn and garden enthusiasts.
• An agricultural summary of the fall months.
• A fall climate summary, including daily highlights.

If this has seemed like a long, cold winter, that's because it has been. OCS and KWTV News9 looked at past winters to see just how this winter compared. Digging back through snowfall records for Oklahoma City from 1948 to present, we've learned just how this winter stacks up to some of the memorable ones from the past.

Even though this winter has been cold (38.9 degrees average temperature from December 1 - February 15), it is far from the coldest. In fact, of the past 60 years, this year is so far tied for 29th coldest - roughly the middle of the pack. However, it may seem colder because Oklahoma City just came off its 3rd warmest winter on record, a balmy 43.2 degree average temperature. You have to go back to 2000-2001 for a colder period, when the average temperature was a chilly 35.0 degrees.

But cold is only part of the story. If it seems like we've had more snow or ice events or the snow/ice has stuck around longer than usual, that is indeed the case. As of February 15, Oklahoma City reported 19 snow days (days with at least 1 inch of snow falling or on the ground). This ties for the 5th most since 1948, and there are still another 4-6 weeks in which additional snow may be possible. The record is 25 days, set in 1948.

The snow/ice also has stuck around longer. The 13 days from January 12-24 where snow (or ice) either fell or was on the ground is the 3rd longest period of consecutive snow-days in modern records. The longest period was 18 days in 1978.

So this winter has definitely been tough, but what was the worst winter? Hands-down, that distinction goes to 1978-1979. That winter was the coldest (30.4 degrees), 2nd for the most number of snow days (23), had 6 snow events, and had 18 consecutive days with snow on the ground. This came right on the heels of the winter of 1977-1978, which otherwise would have been considered the worst winter in modern times. As spring came in 1978, folks were probably grateful to have that winter put behind them, but they had no idea that it could get worse just one year later.

The National Weather Center will host a kick-off event for the Pioneer Multi-County Library System's Big Read event, featuring "The Grapes of Wrath" by John Steinbeck, on Friday, Feb. 9. Scientists will give talks, followed by a reception and tours of the NWC facility, located at 120 David L. Boren Blvd. Geographers and meteorologists from the College of Atmospheric and Geographic Sciences will discuss weather conditions of the Dust Bowl compared with today, accuracy of the conditions portrayed in the book, human impact and farming practices during the Dust Bowl and how these issues affect us today.

Speakers include Gary McManus, a climatologist from the Oklahoma Climatological Survey. Gary will discuss the climate of the Dust Bowl era, and the conditions and practices that led to the Dust Bowl disaster.

John Steinbeck's The Grapes of Wrath is not merely a great American novel. It is also a significant event in our national history. Capturing the plight of millions of Americans whose lives had been crushed by the Dust Bowl and the Great Depression, Steinbeck awakened the nation's comprehension and compassion.

Visit the Big Read website at http://www.bigreadok.com for more information, including registration, online discussions, and updates leading up to the event. Registration for this event is limited to 500. Due to the demand, the presentation in the auditorium will be presented twice: 5:45 and 6:45 p.m.
State Climatologist to Speak on Climate Change
January 30, 2007

Global warming may be the furthest thing from our minds these days, but just a few months ago, it felt very real. State Climatologist Ken Crawford will join climate experts on a panel discussion focused climate change and its implications for Oklahoma. The panel will discuss the current scientific understanding of the dominant causes of climate change and its effects locally, nationally and internationally. This coincides with the February 2 release of the first volume of the Intergovernmental Panel on Climate Change (IPCC) fourth assessment report, "Climate Change 2007: The Physical Science Basis".

Dr. Crawford, Regents Chair Professor of Meteorology at The University of Oklahoma, will be joined by renowned climate experts Dr. Robert Corell, Director of Global Change Programs at the Heinz Center in Washington, DC, and Dr. David Karoly, Williams Chair Professor of Meteorology at the University of Oklahoma. Dr. Corell served as the Chair of the Steering Committee for the Arctic Climate Impact Assessment, an international effort completed in 2005 to evaluate the effects of climate variability and climate change in the Arctic. Dr. Karoly was a lead author and review editor of the forthcoming IPCC report. Also appearing on the panel will be Dr. Mark Shafer, Director of Climate Information from OCS, who will look at climate change from a political and policy perspective.

The IPCC report assesses current scientific knowledge of the natural and human drivers of climate change, observed changes in climate, the ability of science to attribute changes to different causes, and projections for future climate change. Panel members will each give a short presentation, followed by a question-and-answer period. Please join us on Friday, February 2, at 1:30 p.m. at the National Weather Center in Norman. For accommodations based on disability, or more details, please contact the School of Meteorology at (405) 325-6561.
Ice Storm!
January 12, 2007

Freezing rain is a distinct wintertime hazard in Oklahoma. Ice storms are extended freezing rain events, lasting several hours to days at some locations, with heavy ice accumulations. The US National Weather Service considers an ice storm with greater than 0.25 inches (0.63 cm) of ice accumulation a significant episode that would trigger an ice storm warning. The resulting ice cover can down power lines and limbs, causing millions of dollars in damages and widespread power outages. These events make automobile travel very treacherous, especially on secondary roads, where the ice can linger for several days. Significant icing events occur with nearly the same frequency as heavy snow events, especially in the southeastern half of the state. While ice accumulation is usually less than an inch, storms that deposit several inches can occur once or more per decade. The consecutive winters of 2000-01 and 2001-02 each featured a major ice storm that deposited more than three inches of ice in 24 hours across much of southeast and central Oklahoma. For the electric utility industry, an ice storm strikes in two waves: first from the initial ice accumulation and wind stress; then later from stresses caused by the rapid recoil of power lines when accumulated ice melts and falls.

FREEZING RAIN FORMATION

Freezing rain is most commonly found in a narrow band on the cold side of a warm front, where surface temperatures are at or just below freezing (Figure 1).

Whether freezing rain forms from the cold rain or not depends critically on the characteristics of the surface cold air layer. If the layer is too thick or too cold, it will refreeze the rain into ice pellets, or sleet. If the cold layer is too warm or too shallow, the rain will continue to the ground as normal rain and will not freeze unless the temperature of the ground or some other surface it contacts is well below freezing. Often small temporal or spatial differences in air temperature and in droplet size result in freezing rain mixed with sleet, snow or non-freezing rain.

Much-needed rain and snow visited the state during December, lessening drought conditions and providing welcome relief to most of Oklahoma. Between 3-6 inches of precipitation fell over a good portion of the state, while the Oklahoma Panhandle suffered through a couple of bouts of nasty winter weather. That helped the Panhandle region to its wettest December on record, more than three inches above normal. The state as a whole fared well with the 12th wettest December on record. Drought conditions remained severe in parts of north central Oklahoma, which largely missed out on the heavy precipitation. The year ended as the 23rd driest on record statewide at eight inches below normal. The year’s final month was also the 27th warmest on record, helping the year itself to finish as the 2nd warmest.

An inch of freezing rain and up to 5 inches of snow in the state’s three western-most counties on the 19th made for treacherous driving, as well as leaving thousands without power. Still smarting from that wintry blast, a full-fledged blizzard hit the Panhandle on the 29th. Eighteen inches of snow and drifts of up to 6 feet brought much of Cimarron and Texas counties to a standstill. An ice storm hit the rest of the Panhandle, once again leaving thousands without power and destroying over $1 million of power poles and lines.

The Oklahoma Climatological Survey is proud to announce the Fall 2006 edition of its seasonal climate series "Oklahoma Climate," available online at: http://climate.mesonet.org/seasonal_summary.html.

Beat the Heat with these great stories:

• Pacific hurricane remnants have acted as drought busters in Oklahoma's past. Remember Norma?
• OCS partnered with the Oklahoma Insurance Commission to host the Climate and Loss Mitigation Conference. We give a nice recap inside.
• OCS Senior Electronics Technician Ken Meyers has taken some beautiful pictures of the Oklahoma countryside, showcased in our "Photos From The Field."
• EarthStorm has been teaching Oklahoma teachers to use weather data in the classroom since 1992. Follow along with the latest EarthStorm workshop.
• Our "Classroom Exercise" this time around allows students to issue flash flood warnings caused by the remnants of Tropical Storm Dean in 1995.
• Is cloud seeding a viable drought remedy? Read OCS' position statement on cloud seeding inside.
• Wildfire safety tips -- protecting your home.
• Autumn horticulture tips for lawn and garden enthusiasts.
• An agricultural summary of the summer months.
• A summer climate summary, including daily highlights. The drought of 2005-06 reached its peak during the summer.

The beneficial rains of the past several weeks have brought nominal to significant improvement across drought-ravaged Oklahoma. With this relief, the National Drought Mitigation Center (NDCM) lowered the drought severity across most of the state by one to two categories. This past week, NDMC lowered southern Oklahoma's drought designation from "exceptional" - the most severe category - to "extreme". Unusually heavy rains in the Panhandle improved that area's drought impacts from "extreme" to merely "abnormally dry".

Despite the above normal rainfall of August, however, the drought is still labeled as "severe" or "extreme" over a sizable portion of southern and western Oklahoma. Much of the remainder of the state remains in "moderate" drought conditions. In effect, while short-time impacts have lessened, the drought is still dominated by long-term effects due to precipitation deficits that began in earnest in late February of 2005. In some areas of the state, the true drying-out period began much earlier. In the southeast, for instance, the dry period extends back to early 2003.

Statewide average precipitation statistics from the Oklahoma Mesonet ranked the March 1, 2005, through September 10, 2006, interval as the driest-such period on record, 19 inches below normal. While the drought has ebbed and waned over that time, its impacts became especially severe early last fall. Effectively wiping out more than half of the state's wheat crop, the worst harvest in more than 50 years, the drought also provided Oklahoma its worst wildfire season on record. More recently, the western half of the state enjoyed above normal rainfall in August and early September, while the eastern half of the state had very little rainfall. Southwestern and west central Oklahoma experienced their 23rd wettest such periods on record, while the Panhandle enjoyed their 6th wettest.

The long-term drought conditions result in a more difficult road to recovery. Rain that falls in areas with deficits in the tens of inches over the last several years has several levels of water supply to replenish, from soil moisture, surface water, to deep wells and aquifers. And, as evidenced by the Oklahoma Mesonet's soil moisture observations, even short-term improvements can be fleeting if not quickly reinforced by more precipitation.

The latest seasonal drought outlook from the Climate Prediction Center calls for varying degrees of improvement across the northwestern two-thirds of Oklahoma through November, and drought persistence across the southeastern one-third.