Showers and thunderstorms are occurring across the western third of Mississippi, Central Louisiana, western Tennessee and eastern Arkansas this afternoon.
A broad surface low is over Central Louisiana. This low should lift to near Memphis by Midnight. A big bowling ball of an upper low is over Oklahoma. This low will strengthen and move northeast into Kansas and Missouri this evening.
The airmass over Alabama is very stable right now. Showers were beginning to enter Southwest Alabama at this hour. It is quite breezy and it will become moreson as we move into the evening hours.
A strong low level jet will push eastward this afternoon and tonight, pumping copious amounts of moisture northward and maintaining the area of showers and storms.
There have been numerous severe thunderstorm warnings, but few reports of severe weather today. The few reports that have been received have been mainly hail reports.
Tornado watches are in effect for a large area of Southwest and Central Mississippi back into Central Louisiana.
The storms have weakened a bit in the past couple of hours as they move into more stable air, but strong inflow and increasing upper level winds will allow storm activity to continue to intensify during the evening and overnight.
The strongest storms are currently over eastern Louisiana, approaching Baton Rouge and approaching Vicksburg and Natchez. The are moving northeast at 40 mph. On this pace, they will reach West Alabama around 7 p.m. or so.
As the storms push eastward in Alabama this evening, they will initially be elevated, meaning that they are rooted in instability above the surface. These storms can be prolific hail producers as well as being very loud from a thunder standpoint.
Rain and storms will continue to spread northward and northeastward into the early morning hours, as instability levels increase and the storms become surface based, there could be severe weather overnight, mainly along and south of the warm front which will be lifting northward.
The chance for severe weather overnight will be mainly over South Alabama south of a line from Linden to Montgomery to Eufaula, but we can’t rule out a few warnings over Central and North Alabama as well.
There will likely be a break in the rain and storms Monday morning. The airmass over Alabama will destabilize to the south of the northward moving warm front. How far north the front makes it will delineate a large part of the severe weather threat.
The powerful upper system will allow for steep lapse rates and moderate instability levels by Monday afternoon. Storms will form in the unstable air ahead of an approaching cold front. Any storms that form will rotate, thanks to the overall wind shear. All modes of severe weather will be possible Monday, including damaging winds, large hail and tornadoes. We will have to watch the system unfold before we can be more specific.
Suffice to say, that you will want to stay close to a source for weather information overnight and through much of tomorrow.
I would expect that parts of South Alabama would see the slight risk outlook area upgraded to moderate in later issuances by the Storm Prediction Center.
