Monday, December 08, 2008

Strong to Severe Storms Possible

WRF, valid midnight Tues/Wed.

On this Monday morning temperatures were well down into the 20’s across most of North and central Alabama with frost reported in many areas. My low in Vinemont this morning was 27 with scattered frost. Don’t let the cold air this morning fool you. As long time residents and those of us who watch the weather closely know, weather can change quickly in Alabama, and that is certainly true in the month of December.

A rather dynamic trough is building to our west and the Storm Prediction center has placed portions of Texas, Oklahoma, Arkansas, and Louisiana under a “slight risk” for severe weather this afternoon. A dryline has formed which will be overtaken by a cold front later tonight.

Ahead of the dryline, the air is warming and moisture is increasing. Later this evening instability values in the Alklatex region may be in the 1000-1200 j/k range, which is certainly enough to produce severe weather if the other parameters are in place. It appears that a strong subtropical jet will provide sufficient lift and wind shear will be present.

As a result, the SPC is predicting a few supercells capable of damaging wind and severe hail. After midnight tonight, the SPC believes a few tornadoes may be possible across Eastern Texas and into the Arklatex region.

This environment will push eastward through the day Tuesday and set up a potential severe threat for Southern Arkansas, Louisiana and South and central Mississippi.

Strong to severe storms will be possible in Alabama overnight Tuesday and into the early morning hours on Wednesday. It looks like the best chance of precipitation in Alabama will be between 9 p.m. Tuesday and 6 a.m. on Wednesday.

Models are showing that much of North and Central Alabama may receive in excess of 2 inches of rain from this system. That is great news considering that many areas remain over 10 inches below average rainfall so far this year.

This is an important forecast and all residents of Alabama should have a way to hear severe weather warnings on Tuesday night and Wednesday morning. Sadly many people are killed because they do not take shelter in overnight severe weather events. Remember that strong straight line winds can blow trees on top of homes.

Nice site for accessing model data.


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