Wednesday, May 30, 2012

Tornadoes, Hail are Big Threats Today for Plains

Overall Risk of Severe Weather

Risk of Hail

Risk of tornadoes

Risk of damaging winds
There is a moderate risk of severe thunderstorms as outlined by the Storm Prediction Center for the Southern Plains today. The risk does appear to stem from a tornado and hail threat, more so on the hail threat.

A low pressure system will be stationed in northern Texas, with an occluded front stretching horizontally from central Oklahoma through the Carolinas. As the low pressure center approaches the moderate risk area, a dryline will come out just ahead of the low pressure system. At this point, the front is separating cold and warm air, and the dry line is separating dry and humid air. That makes 2 boundaries separating all types of air masses. Needless to say, that will spark a severe weather event.
The proximity of the front and dry line to the low pressure system lead me to believe that any storms that form may be influenced by the low pressure system's wind field, thus possibly enhancing the risk for tornadoes.

Valid 8:00 PM CDT
At 4:00 PM CDT, a member of the WRF ensembles begins initiation of showers and storms in western Oklahoma. At 5:00 PM CDT, it is evident that these showers and storms may be taking on supercell characteristics, and by 8:00 PM CDT, the storms have merged into a bowing segment or multi-cellular segment. A multi-cell cluster would enhance a hail risk while a bowing segment would enhance wind risk, so this may be a multi-cell cluster.
I used this graphic after comparing its forecasts for now to what was actually happening now, as this ensemble member ran at 0z.

Chase Spot: Weatherford, Oklahoma



Lucas Reynolds said...

It will get interesting this afternoon and evening, like what you said Andrew, because of those fronts. The updated convective outlook for today hasn't changed except that the damaging wind potential is greater in west central Oklahoma, there is a hatched area also in Oklahoma. The tornado threat has also decreased very little. Have a good and safe day Andrew. Everyone else also stay safe escpecaly in Oklahoma, again.

ERN WX said...

Ok everyone. Disco on Fir svr threat. Do not have much time. Shear aoa 40kts, cape aoa 1500 jkg, good ehi values, dpts aoa 60, all make things dangerous. SPC should have issued mdt risk. SREF sprcl params, idicate sprcls will be likely ahead of the squallline. A few strong torns are poss. 10-35 torn I expect. Wind and hail too. I will have any reports and will be active tomm.