Tuesday, February 17, 2009

Severe Storm Potential Tomorrow in Alabama

SPC SREF Calibrated Probability of Severe Thunderstorms
Valid Noon until 3 p.m. Wednesday 2/18/09

SREF - Craven-Brooks Significant Severe Index valid 3 p.m. Wednesday 2/18/09

Much of the deep South is under a slight risk for severe storms tonight and tomorrow. The SPC pulled back on the threat of hail for Northwest Alabama tonight in the most recent Day One outlook. The entire state of Alabama remains in a slight risk area tomorrow. It appears that storms may come in two rounds. The first round may occur in association with a warm frontal boundary tonight. The second (and most likely severe) round of thunderstorms will move across the state tomorrow afternoon, possibly in association with a pre-frontal dryline.

I may be sounding like a broken record but the biggest issue is how well the instability axis phases up with the vertical wind shear. The SPC does mention the possibility of a few isolated supercells tomorrow. One limiting factor, especially in the Tennessee Valley, may be the storms that are anticipated overnight tonight. Evaporative cooling from those storms may inhibit development ahead of the main boundary tomorrow afternoon. Further south, the chances of instability levels reaching values sufficient for pre-frontal development are higher.

Looking at the latest SREF guidance, the best chance of severe weather in Alabama will be roughly between Noon and 6 p.m. tomorrow afternoon. West Central Alabama and points south and east of there seem to be in the greatest risk area. A few tornadoes are possible, especially in Central and South Alabama tomorrow.

All residents of the State should be aware of the weather and be sure to be in a position to hear watches and warnings that may be issued by the National Weather Service. NOAA Weather Radio and local television stations are good sources for weather information.



Anonymous said...

Hope all goes well.

Mike Wilhelm said...

Thanks Chris.