Monday, February 21, 2011

Severe Weather Likely Thursday...

Computer forecast models and other data continue to indicate that an organized, potentially significant severe weather episode is likely across portions of the Southern Plains, Lower and Middle Mississippi Valley and portions of the Tennessee Valley beginning Thursday afternoon and evening.  

Below is the latest severe weather threat area for Thursday and Thursday Night, as outlined by the SPC in Norman, OK:

Below is the latest surface frontal boundary map, generated by the HPC and valid 6am CST this Thursday:

Warm, moist air will be flowing Northward ahead of the cold front and dryline across Texas into Oklahoma, Arkansas and Louisiana.  By late afternoon, vigorous thunderstorms are likely to develop along both the cold front and dryline from northcentral or northeast Texas across eastern Oklahoma and into western Arkansas.  This activity will then move/develop East/Northeast across the remainder of the severe weather outlook area as the evening and overnight hours progress.

A strong band of winds associated with a strong mid and upper-level weather disturbance will also be lifting across the region at the same time:

GFS Computer Model Forecast, Valid 12 Noon CST Thursday, 2-24

The brighter purple shaded region from southwest Texas into extreme southeast Oklahoma represents the computer model's estimate of a strong band of Southwest winds of 80+ mph located in the mid-levels of the atmosphere.  The wind at the surface will be out of the Southeast, and this strong turning of the wind direction with height will result in a risk of tornadoes with some of the stronger storms.

Here is the same general idea, presented in 3D by the NSSL:

Residents of the severe weather risk area should remain alert and listen for later updates, forecasts, watches and warnings as Thursday approaches.

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