…WINTER WEATHER ADVISORY BIRMINGHAM METRO TONIGHT AND TOMORROW MORNING…
You have to love the Southern U.S., with our rapid weather changes. On one map covering mainly AL and parts of GA and MS, we have Winter Storm Warnings, Flood Warnings, and Tornado Warnings at the same time. Take a look at the chart below, showing observed and forecast temperatures by hour from 2 pm yesterday (80) to 6 am tomorrow morning (31).
The weather system that brought storms last night has moved through, but now an upper-level system to our west is associated with another, intensifying area of precipitation.
The cooler air has already moved in, with temperatures in Birmingham currently in the 50s. But if one goes up I-22 to Memphis, it drops quickly! 43 in Haleyville, 39 in Tupelo, 30 in Memphis. Several stations in west Tennessee have been reporting snow or freezing rain during the past hour.
The above charts, both model predictions for 9 pm CST, show an intense upper-level wave approaching, and a surface low forming along the cold front in south Georgia. This is not the classic setup for a winter storm in Alabama, but with cold air moving in quickly and the forcing from the upper wave, expect precipitation, heavy at times, to spread across north and central Alabama between 4 and 7 pm. Surface temperatures will not drop below freezing until midnight, but lower atmospheric temperatures will be cold enough for snow in NW Alabama by 6 pm, and in BHM by 9 pm. The heaviest snow will likely fall in the Birmingham area between 10 pm and 2 am.
The ground is very warm. However, UAH research has shown that surface and road temperatures respond fairly quickly to falling temperatures, especially with wind. Most of the significant snow accumulation will be north of Cullman, and it will just be pretty to watch in Tuscaloosa, Birmingham and Anniston. But there will be scattered locations where heavier snow occurs, especially on mountains in central Alabama, where 1-2″ of snow may accumulate. I can’t remember a time when it snowed one day following 80 degree temperatures!
Temperatures will be freezing at the morning rush hour, so there may be ice on roads, especially bridges. I think all the kids are out of school tomorrow. If you have to go to work in the morning, please check the weather and road conditions, and go in late if you can. Temperatures will go above freezing by 11 am or so tomorrow in most areas.
Dr. Tim Coleman
Coleman Knupp and Dice LLC