Winter Weather Update – Midnight

Got the bag of caramels and the diet Canada Dry for a long night of watching the weather across North and Central Alabama as we deal with the possibility of a sneaky winter weather system that threatens to bring a mix of precipitation to the area through Saturday morning.

LATEST TEMPERATURES

As you can see from the MesoWest graphic, temperatures are already near or below freezing generally north of a line from Haleyville to Smoke Rise then back up I-59 into Northeast Alabama. Dewpoints are low enough for a 1-2 degree temperature drop as the lower levels of the atmosphere become saturated as moisture moves in from the southwest overnight. This means that these areas will likely see snow flurries, light snow and some sleet overnight

PRECIPITATION

Radar echoes are definitely increasing tonight over Mississippi into West Central Alabama. Precipitation is beginning to break out in northern Lamar into Marion and over Walker County as well. Precip north of Meridian is poised to move into Pickens County. Precipitation is breaking out back near Greenwood MS. Everything is moving northeast and will overspread the northern half of the state overnight.

TEMPERATURES ALOFT

This graphic shows temperatures at 5,000 feet, an important level for snow at the surface. It shows that temperatures are well above freezing over the northern half of the state. In fact, you don’t get to subfreezing until you get into Tennessee. The precipitation will fall as rain. In areas that are below freezing at the surface, it will fall in a liquid form that freezes on contact to exposed surfaces, meaning freezing rain. If the surface cold air is deep enough, it could refreeze before reaching the surface, resulting in sleet. This means that as the atmosphere moistens, precipitation will start out as freezing rain or sleet during the early morning hours until the colder air aloft works its way into the area, changing the precip over to snow.

BOTTOM LINE

We will see light freezing rain or sleet through the early morning hours over parts of Lamar, Marion, Walker, northern Jefferson, Blount, St. Clair, Calhoun and Cleburne Counties and points north. This area could extend down into Talladega, Clay and Randolph Counties, perhaps as far south as Ashland and Wedowee.

This precipitation will gradually change over to snow from the northwest during the predawn hours. Light accumulations are expected generally. There could be bridge icing problems during the early morning hours north of a line from about Millport to Gardendale to Anniston line. The rest of the Birmingham Metro will be right on the borderline for potential problems.

South of this area, the precipitation should be mainly rain, with some snow mixed in along the northern periphery.

TRAVEL PLANS

If you are heading out early Saturday morning, get up a little early and check the forecast and current conditions. Postpone travel if bridges become slippery. Everything will end by mid to late morning as temperatures warm. Skies will actually clear in the afternoon and highs should make it into the 40s.

Category: Alabama's Weather