James Spann: Northwest Alabama under ice storm warning; severe storms possible in southern part of the state

WILD WEATHER WEEKEND AHEAD: We have a mix of sun and clouds across Alabama with temperatures ranging from the upper 40s across the Tennessee Valley to 70 degrees at Gulf Shores. Clouds will increase tonight ahead of a wild weather weekend.

Here are the key messages…

*An ice storm warning is in effect for Lauderdale, Colbert and Franklin counties (the northwest corner of the state)

*A winter weather advisory is in effect for Lamar, Fayette, Marion, Winston, Walker, Lawrence, Limestone, Madison, Marshall, Morgan, Cullman, Blount, Etowah, Cherokee, Jackson and DeKalb counties (the northern third of Alabama).

*A winter storm watch is in effect for Calhoun and Cleburne counties.

*Light freezing rain will move into Northwest Alabama tomorrow morning between 6 a.m. and 8 a.m. The greatest risk of significant ice accumulation is over the northwest corner of the state, where Lauderdale, Colbert and Franklin counties are under an ice storm warning.

*The latest model guidance suggests these three counties could see freezing rain from tomorrow morning until around midnight tomorrow night. Ice accumulation of .25 of an inch to .40 of an inch is likely, which is enough to bring down some trees and power lines and create very icy travel. Temperatures will slowly rise tomorrow night, and the northwest corner of the state should be above freezing from around midnight through mid-afternoon Sunday, which could help to ease icing conditions to some degree. But, understand 10-12 hours of freezing rain seems likely around the Shoals, which will create a very high impact ice situation.

*Elsewhere, some scattered, light freezing rain is possible tomorrow where a winter weather advisory is in effect for the northern third of Alabama. Generally north of a line from Millport to Jasper to Oneonta to Gadsden to Centre. This could lead to a few icy spots, mainly on bridges. This winter weather advisory does NOT include Birmingham or Tuscaloosa, where we expect just rain.

*Temperatures should be generally above freezing over the northern half of Alabama from around midnight tomorrow night through noon Sunday, but the cold air damming effect (CAD) could bring in colder air into parts of Northeast Alabama from the east. Some freezing rain and icing is possible tomorrow night across parts of Jackson, DeKalb and Cherokee counties.

*A winter storm watch is in effect for Calhoun and Cleburne counties in the event cold air moves into those counties from Georgia tomorrow night. A very conditional threat for some freezing rain there.

*More cold air will rush into the state Sunday afternoon through Sunday night; a brief change to freezing rain or light snow is possible in the colder air before it all ends.

*A flash freeze/black ice situation is very possible Sunday night and Monday morning over the northern half of the state as temperatures drop into the teens, resulting in standing water freezing on bridges and some roads.

*A few severe thunderstorms are possible over South Alabama Sunday ahead of the cold front. Heavier storms will produce strong, gusty winds, and a brief, isolated tornado or two can’t be ruled out. There is a “marginal risk” (level 1/5) of severe thunderstorms for parts of South Alabama.

Next week will be dry but very cold with temperatures well below average. We do note a few global models are hinting at potential for more wintry weather across the Deep South next weekend, but it is way too early to know for sure. See the video briefing for maps, graphics and more details.

ON THIS DATE IN 2012: A total of 11 tornadoes touched down in Alabama, mostly during the pre-dawn hours. One person was killed by an EF-2 tornado near Oak Grove, in western Jefferson County. The strongest tornado of the event (an EF-3) moved through Center Point, and parts of Clay and Trussville; a 16-year-old girl was killed, and 75 others were injured. Center Point Elementary School had the southwestern portion of its roof completely removed. A total of 231 homes and businesses were damaged or destroyed. The tornado damage path was approximately 15.5 miles long and was 880 yards wide at its widest point.

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