James Spann: Alabama weather unsettled, with strong storms possible from Alabama NewsCenter on Vimeo.

COOL, DREARY, DAMP DAY: We begin this Monday with low clouds, fog and drizzle across much of North/Central Alabama. Temperatures are mostly between 46 and 51 degrees; they haven’t changed much over the past 24 hours.

Showers will increase later today as a surface low forms west of the state; that low will move from near Lake Charles, Louisiana, this morning to Muscle Shoals late tonight. A warm front, extending eastward from the low, will lift northward later today and tonight, putting the southern half of the state in a warm, unstable airmass. And that will set the stage for active thunderstorms tonight.

SEVERE WEATHER THREAT TONIGHT: The Storm Prediction Center has the standard “slight risk” of severe weather defined for areas south of a line from Demopolis to Verbena to Auburn, with a “marginal risk” to just north of Birmingham.

All modes of severe weather will be possible over the southern half of the state tonight, including storms with large hail, damaging winds and a few tornadoes. The risk is much more limited along the I-20 corridor (Tuscaloosa, Birmingham, Anniston) as the most unstable air remains just to the south, and for now we don’t expect any severe weather issues for the northern third of the state.

The main window for severe storms over South Alabama will come from about 10 tonight through 6 tomorrow morning; be sure you have a way of getting warnings (NOAA Weather Radio, a good smartphone warning app like WeatherRadio by WDT) since this will come during the late night and pre-dawn hours.

TOMORROW/WEDNESDAY: Rain and storms will end early tomorrow morning as the surface low pulls away; clouds will linger much of the day, although we could see late afternoon clearing. The high tomorrow will be in the low 60s. Then, on Wednesday, the day will be cool and dry, but only a limited amount of sun is expected. Wednesday’s high will be in the mid to upper 50s.

ARCTIC AIR BLAST ARRIVES THURSDAY: An Arctic front will blow through Alabama Thursday. Moisture will be limited, but some light rain could accompany the front; then, after its passage, strong north winds will kick in and usher in the coldest air so far this season. We will have a hard time getting past the low 40s Thursday afternoon, and a north wind of 15-30 mph will make it feel colder. By Friday morning we should reach the low 20s, and during the day Friday we won’t get out of the 30s despite sunshine in full supply. Some communities up in the Tennessee Valley of far North Alabama could stay below freezing all day Friday.

By Saturday morning, expect a low between 18 and 22 degrees across North/Central Alabama.

THE WEEKEND: Saturday will be sunny with a high in the upper 40s; clouds will begin to increase Sunday, but for now the weather looks dry with a high back in the 50s.

NEXT WEEK: Another rain event should unfold Monday, with potential for a few storms Tuesday as the air becomes unstable. Then, more cold air is due in here over the latter half of the week.

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