Severe Storms Possible Tuesday Night

This is an early look at the threat of strong to severe thunderstorms across Alabama Tuesday night and early Wednesday morning…

SETUP: A deepening surface low will pass just northwest of Alabama, moving through North Mississippi and West Tennessee Tuesday night, supported by a deep upper trough. The low level jet (about 5,000 feet off the ground) will ramp up to over 50 knots Tuesday night, with storm relative helicity (0 to 1 km) values exceeding 400 m**2/s**2.

As is usually the case, the amount of surface based instability is in question, but surface dewpoints are expected to reach the low 60s, with surface based CAPE values over 500 j/kg.

TIMING: The main threat of severe storms in Alabama will come generally in the 12 hour window from 9:00 p.m. Tuesday through 6:00 a.m. Wednesday.

PLACEMENT: Highest risk of severe storms will be along and south of I-20 (Tuscaloosa to Birmingham to Anniston), where instability values will be higher.

MODES: The main threat will come from damaging straight line winds with a squall line moving through during the late night hours, but a tornado or two is certainly possible, especially in any discrete storms that form ahead of the line.

Please understand this is an early look at the situation, and this could easily change as we get closer to the event. Just know we will have the risk of strong to severe storms late Tuesday night into early Wednesday, and you might want to be sure your NOAA Weather Radio has a fresh battery, and is programmed properly since this will be an “overnight” event for many. Have a good app designed for warnings on your phone, like WeatherRadio by WDT or MyWarn.

Keep an eye on the blog and we will keep you posted…

Tags: ANC, storms

Category: Alabama's Weather