James Spann: Potential for heavy rains/strong storms Friday; colder Sunday in Alabama

MILD WINTER DAY: Temperatures are in the 70s over the southern 2/3 of Alabama this afternoon with a mix of sun and clouds. No rain on radar at mid-afternoon. The sky becomes mostly cloudy statewide tonight with potential for more fog after midnight.

Not much change tomorrow; a very mild January day with only isolated afternoon showers after low clouds/fog/drizzle early in the day.

FRIDAY/SATURDAY: A slow-moving cold front will bring potential for heavy rain and strong thunderstorms to the northern 2/3 of Alabama. The Tennessee Valley will have potential for over 3 inches of rain, with 2-3 inches likely down to places like Birmingham, Tuscaloosa, Anniston, and Gadsden.

Some flooding issues could very well develop Friday night and early Saturday over some northern counties. Rain amounts for South Alabama will be much lighter.

SPC continues a “slight risk” (level 2/5) of severe thunderstorms west of a line from Huntsville to Birmingham to York, with a “marginal risk” (level 1/5) down to Ranburne, Montgomery and Gulf Shores.

The severe thunderstorm risk is somewhat conditional; instability values are rather low, which will be a limiting factor. But we note models show a strong low-level jet (winds about 5,000 feet off the ground) setting up over Alabama Friday night, which will aid in thunderstorm development. The main risk will come from strong, gusty winds; a brief isolated tornado can’t be totally ruled out in the level 2/5 risk area IF the air is unstable.

Showers and storms will end Saturday from the northwest; by afternoon most of the rain will be over the eastern and southern counties of the state. Sunday will be sunny, breezy and much colder with highs in the 40s and 50s. A freeze is likely over the northern 2/3 of Alabama by early Monday morning.

NEXT WEEK: While there could be some scattered light rain Wednesday or Wednesday night, much of the week looks dry with seasonal temperatures. Highs generally in the 50s, lows mostly in the 30s. See the video briefing for maps, graphics and more details.

ON THIS DATE IN 2014: Bitterly cold Arctic air was in place across Alabama. Huntsville dropped to 4 degrees; Birmingham’s low was 7. Three weeks later would come “Snowmageddon”, which would cripple the Birmingham metro due to a flash freeze on roads.

For more weather news and information from James Spann and his team, visit the Alabama Weather Network.