Severe Threat Followed by Winter Weather Threat

An impressive storm system is ramping up to our northwest right now with a rapidly deepening upper trough over Iowa that is forming a big upper low. At the surface. a strengthening surface low over eastern Iowa will be moving northeastward and intensifying.

Big snows are occurring over the Upper Midwest and Great Lakes. Extremely cold air is rushing southward in the wake of this system.

Thunderstorms are intensifying the warm sector of the storm system over western Mississippi and Northeast Louisiana, where a tornado watch is in effect. A couple of tornado warnings are in effect in western Mississippi and extreme eastern Louisiana. Other severe thunderstorm warnings are in effect along the developing line of storms that is pushing east at 35 mph.

There is barely anything in the way of instability until you get well into Central Louisiana, but very strong winds aloft ahead of the intensifying storm system will produce the threat of a few tornadoes in Mississippi, along with a threat for damaging winds. This line will reach West Alabama before 9 p.m. tonight. There is even less instability over Alabama, but we will deal with the threat of damaging winds as the line pushes into the state.

Then the threat will shift to a winter weather one for Alabama. Here are the potential winter hazards…

COLD
…Temperatures will fall quickly to freezing behind the front as it enters the state late tonight. Lows by morning will be in the upper 20s over the West to middle 30s over the East. Readings on Sunday will struggle to stay above freezing and then fall into the 13-17F range Sunday night. In addition, a strong northwesterly wind at 15-25 mph occasionally gusting to over 30 mph will make wind chill temperatures fall into the teens on Sunday and to near 0F Sunday night over North and Central Alabama. Wind chill advisories may be necessary for Central Alabama on Sunday and a wind advisory has already been posted. In addition, a hard freeze watch is in effect for late Sunday night into early Monday morning for all of Central Alabama.

BLACK ICE
…Most areas should see between one half and an inch of rain tonight as the showers and storms pass. This, combined with the flash freeze will produce area of ice on area roads starting by early Sunday morning. Remember that bridges and overpasses freeze first. This threat will be with us into Monday.

SNOW
…There may be a brief changeover to snow on before the main precipitation ends over North Alabama after 3 a.m. Sunday morning. In addition, snow showers will continue in the wraparound moisture through the day over areas north of a line from Carrollton to Roanoke. The NWS Huntsville warns that accumulations could amount to one inch over the Tennessee Valley of North Alabama with locally higher amounts over Northeast Alabama, in places like Jackson and DeKalb Counties. They have posted a winter weather advisory for their counties in North Alabama, including Colbert, Cullman, DeKalb, Franklin, Jackson, Lauderdale, Lawrence, Limestone, Madison, Marshall and Morgan Counties.

This is an evolving storm situation that needs to be carefully monitored for its impacts on you and your family. Pay attention to the latest forecasts, advisories and warnings over the next 72 hours.

Category: Severe Weather, Winter Weather