After what has turned out to be a great weather day on our Thursday, things rapidly change again tonight. The next weather system approaches, and widespread rain moves into the area by late evening and continuing through the overnight. Some of the rainfall may be locally heavy at times, and there may even be a few thunderstorms involved, especially over our Mississippi and Alabama counties. That heavy rain looks to continue through the morning hours before gradually tapering off as we head into the midday. We can't rule out a few showers during the afternoon, but many of us may catch a break in the rain before the next system moves in Friday night.
By evening on Friday, a few showers start to move back into the area as the frontal boundary works north toward our region. During the late evening and overnight, thunderstorms develop back over north Mississippi, and these move northeastward along the front into southern Tennessee and maybe northwest Alabama during the late night hours and into the early morning of Saturday. These thunderstorms look to train along the same areas, and this repeated heavy rain after earlier heavy rain during the morning on Friday may set up the potential for some localized flash flooding.
In addition, a few of the storms may be strong as well during this timeframe. The Storm Prediction Center has placed the area in a Level 1 of 5 risk of severe storms. Because of cool, stable air at the surface, the thunderstorms won't be rooted at the ground level. That makes it very hard for any type of tornado threat. We can never 100% rule out anything, but the tornado threat is as close to zero as is physically possible. The warm, humid, unstable air is rooted a few thousand feet above the ground level. Above the cool, stable surface layer, there is enough instability for strong storms, and there is enough wind shear in the atmosphere to organize those strong storms. Because of that, we can't completely rule out a few of them having the potential to produce hail of up to quarter size or a touch larger, or maybe one or two storms having gusty winds of 40, 50, maybe even 60 mph.
This frontal boundary stalls near the area over the weekend and even going into early next week. Multiple disturbances will ride along the front, bringing with them rounds of locally heavy rainfall and thunderstorms. A good 4 to 6 inches of rain is likely across much of the area between tonight and early next week, and where thunderstorms train at times, there may be higher amounts. The overall risk of flooding and flash flooding will likely increase areawide by late in the weekend and early next week, in addition to localized flooding concerns as early as Friday night and Saturday morning from any training thunderstorms.