 | Southwest Oklahoma Heat Burst of May 22-23, 1996 |
Event Summary:
On the afternoon of May 22, 1996, thunderstorms formed along the dryline in the
southeast Texas Panhandle. These storms intensified to severe limits as they propagated to the north and east into southwestern Oklahoma over the next several hours.
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| Visible GOES-8 Image at 5:45 p.m. CDT. | Base Reflectivity from Frederick (KFDR) WSR-88D at 7:03 p.m. CDT. |
| KFDR 0003 GMT (7:03 p.m. CDT) | KFDR 0102 GMT (8:02 p.m. CDT) | KFDR 0310 GMT (10:10 p.m. CDT) | KFDR 0505 GMT (12:05 a.m. CDT) | KFDR 0603 GMT (1:03 a.m. CDT) |
When the thunderstorms dissipated, they forced large quantites of dry air from aloft towards the surface. The Norman 7:00 p.m. upper-air sounding indicates a significant dry and warm layer of air between 850 and 700 mb. This dry air may have played a role in the significant warming that occurred at the surface later. The thunderstorm downdrafts caused the air to warm dramatically as the air was compressed. Damaging wind gusts occurred as the downward-directed air hit the ground and spread out horizontally. These phenomena (known as heatbursts) typically are not detected by the regular Federal surface weather observing stations, but a denser network like the Oklahoma Mesonetwork can easily detect the increasing temperatures and high winds.
Oklahoma Mesonet Observations
The high winds produced by this heatburst produced sigificant damage over a large part of southwest Oklahoma. For details, see these Local Storm Reports issued by the Oklahoma City National Weather Service. This heatburst (or sequence of heatbursts) was stronger, covered a larger area, and spanned a longer period of time than most heatbursts, as the following Mesonet observations indicate. A Mesonet station model plot of temperature, dew point, and wind gusts at 9:25 p.m. reveals that Chickasha was 102 ° F, and Ninnekah was 99 ° F. Approximately three hours later, the same area experienced severe wind gusts. The Mesonet plot at 12:45 a.m. shows winds gusting over 60 mph at Chickasha, Ninnekah, and Acme. The extent of the high winds are given in this summary of Mesonet severe wind reports. Station Model Plots
Mesonet Temperature Contours and Wind Vectors at 15 minute intervals. (1.3 MB QT Movie)
Meteograms
A time summary of the event is presented in these meteograms.
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| Norman: 3 distinct wind pulses: 10:00 p.m, 1:00 a.m. and 2:15 a.m. Temperature rose to 92.4 ° F at 12:35 and to 98.6 ° F at 2:20 a.m. Peak wind gust was 40.7 mph at 2:45 a.m. |
Chickasha: At 9:25 p.m. air temperature at 1.5 m was 101.9 ° F and was 100.2 ° F at 9 m. The 1.5 m temperature was above 90 ° F between 9:20 p.m. and 2:25 a.m. The winds gusted above 60 mph at 9:50 p.m., 10:00 p.m., 10:20 p.m., 12:45 a.m., and 12:50 a.m. |
| Acme (ACME) |
Altus (ALTU) |
Apache (APAC) |
| Chickasha (CHIC) |
Fort Cobb (FTCB) |
Hobart (HOBA) |
| Ketchum Ranch (KETC) |
Ninnekah (NINN) |
Norman (NORM) |
| Tipton (TIPT) |
Washington (WASH) |
ARS Micronet Observations
The Oklahoma Mesonet operates a network of 42 weather stations for the Agricultural Research Service (ARS) of the United States Department of Agriculture (USDA). This micronet, located in Grady, Caddo, and Comanche Counties (in the Little Washita River Basin), measures rainfall, temperature, relative humidity, solar radiation, and soil temperatures.
The ARS station model plot at 9:25 p.m. shows station A146 at 100 ° F, the 102 ° F reading from the CHIC Mesonet site, and 31 stations at or above 90 ° F.
Other Mesonet Case Studies
This page was produced by Dale Morris. The Mesonet severe wind summary was provided by Putnam Reiter, and the ARS plots were provided by Justin Greenfield.