Rain is knocking on the door to the Tennessee Valley on this Wednesday morning! You can see a complex of moderate to heavy rain over southwest Tennessee back into north central Mississippi with strong thunderstorms trailing it southward through southwest Mississippi into Louisiana. This will be our big ticket weather item for today. A FLOOD WATCH continues across our entire viewing area for today all the way through Thursday evening for the likelihood of locally heavy rainfall that may cause both flash flooding and larger overall areal flooding. Estimated rain totals have come down a little bit compared to what they looked like earlier in the week for this period, but a good 1.5 to 3 inches of rain is still likely through tomorrow evening, and we can’t rule out isolated heavier totals, especially over north Alabama. Because of the recent snow/ice melt and how that has saturated the ground, it would only take 1 to 2 inches of rain to cause flooding issues because very little will be allowed to absorb into the ground and will runoff instead.
Above is an overall breakdown of timing of the rain for today, tonight, and into Thursday from the high resolution HRRR forecast model. You can go through the images from top left to bottom right, as well as click on them to make them full sized for better viewing. The heaviest rain during this ordeal looks to be from the mid to late morning today through the early evening, but lingering showers are possible overnight. Additional locally heavy downpours are possible Thursday, but they likely won’t be as widespread as the rainfall today.
And in case you’re wondering, there is NO severe storm threat across our area with this system for today or tomorrow. Southern areas of Mississippi and Alabama have lower-end risk areas in place from the Storm Prediction Center, but even there, it’s a very marginal and lower-end threat. No, we don’t expect this to change. No, these risk areas will not shift northward up into our area. We do not have the instability needed or the dynamic support needed for a severe storm threat in the Tennessee Valley. That means no tornado threat here, no damaging wind threat here, no hail threat here. Just the potential for localized flooding and flash flooding with the heavy rain, but that is important enough itself!
We’ve judged down rain chances for Thursday a bit because activity doesn’t look quite as widespread, but rain chances are still elevated. We look to get a brief break in widespread rain during the day on Friday, but a few showers will be possible. A more organized rain event will move back in Friday night into Saturday ahead of a low pressure and cold front. There’s no severe storm threat expected in our area with that system either, but that may bring another inch or more of rain, and it may increase the flooding threat a bit again. After that, we shift back to drier weather from Sunday into early next week.