Oklahoma monthly climate summary, 05/2013

              Copyright © 2013 Board of Regents of the University of Oklahoma.
Oklahoma Monthly Climate Summary 1
In a state so accustomed to highly variable and often tumultuous weather, May 2013 will be long remembered as one of its most notorious. The month began with some of the coldest late-spring weather in the state’s history and finished with a flourish of violent weather, including one of Oklahoma’s worst tornado disasters on record. Stirring the echoes of May 3, 1999, for many central Oklahoma residents, a massive and violent tornado churned its path of destruction from near Newcastle through south Oklahoma City and Moore before dissipating near Stanley Draper Lake. The tornado reached EF5 level, the strongest category on the Enhanced Fujita Scale. The tornado had winds estimated at over 200 mph and reached a maximum damage width of 1.3 miles. State officials confirmed 24 fatalities due to the twister. The storm injured over 300 others with preliminary damage estimates totaling over $2 billion along its 17 mile, 40 minute path. The twister destroyed two Moore elementary schools, killing seven schoolchildren at Plaza Towers elementary and injuring many others. One day previous to that event, a violent twister traveled from east Norman to near McLoud causing two fatalities. That tornado was rated as an EF4. While numbers are still preliminary, the National Weather Service counted at least 19 tornadoes between the two days. Officials from the
OklahomaClimatological Survey
MAY 2013
Oklahoma Monthly Climate Summary
May 2013 Statewide Extremes
Description
Extreme
Station
Day
High Temperature
106ºF
Altus, Tipton
31
Low Temperature
22ºF
Boise City, Hooker, Kenton
3
High Precipitation
12.35 in.
Oklahoma City East
--
Low Precipitation
0.08 in.
Hooker
--
May 2013 Statewide Statistics
Temperature
Average
Depart.
Rank (1895-2013)
Month (May)
66.8ºF
-1.1ºF
37th Coolest
Season-to-Date (Mar-May)
56.3ºF
-2.8ºF
11th Coolest
Year-to-Date (Jan-May)
50.0ºF
-1.1ºF
37th Coolest
Precipitation
Average
Depart.
Rank (1895-2013)
Month (May)
4.92 in.
-0.29 in.
54th Wettest
Season-to-Date (Mar-May)
10.65 in.
-1.03 in.
53rd Wettest
Year-to-Date (Jan-May)
15.55 in.
0.66 in.
36th Wettest
Depart. = departure from 30-year normalresulted in widespread flash flooding. At least two deaths were blamed on flash flooding from the event, with more possible as searches continued.
May saw a continuation of the cool weather and drought relief the state has experienced since mid-February, although western Oklahoma and the Panhandle remained parched. According to preliminary data from the Oklahoma Mesonet, the statewide average temperature finished at 66.8 degrees, more than a degree below normal. May was the fourth consecutive month to finish with below normal temperatures, a feat not seen in Oklahoma since the four month period between December 2009 and February 2010. The below normal finish was mainly due to a cool first half of the month, particularly during the first week. A freeze occurred across western and northern Oklahoma as late as May 3, with temperatures dropping into the 20s as far south as the Red River. Up to 2 inches of snow fell across northeastern Oklahoma on that day, the latest snowfall on record for many locations. Tulsa recorded its first ever May snowfall with a trace on May 2. Numerous records were broken for lowest minimum and lowest maximum temperatures during those first few days of the month. The climatological spring season of March-May finished with a statewide average temperature of 56.2 degrees, nearly 3 degrees below normal, to rank as the 11th coolest on record. Oklahoma Department of Emergency Management estimated that the two-day barrage impacted 2937 homes, businesses and non-residential buildings. The severe weather was far from over, unfortunately. May’s final three days saw a flurry of dangerous weather, culminating on its final day. A large tornadic supercell spawned several tornadoes from El Reno to Moore to southeast Oklahoma City. A preliminary count of nine fatalities from those tornadoes, including two children, brought the year’s tally to at least 35. That ties 2013 with 1960 as Oklahoma’s second deadliest tornado year since 1950, bested only by 1999’s 42 fatalities. The stationary supercell produced prolific rainfall amounts across Oklahoma City and