A Flash Flood Watch has been posted for all of north Alabama from 4am to 7pm Thursday for the anticipation of heavy rain being brought to the area from the remnants of what was once Tropical Storm Beta. An Areal Flood Advisory has also been issued for portions of southern Tennessee that include Giles and Marshall Counties of our coverage area. It is possible that Flash Flood or Flood Watches could be expanded across more of our viewing area as we go forward in time.
Our high resolution in-house Futurecast model shows more widespread and steady rain moving in by the early to mid evening, with heavier rain starting in northwest Alabama and northeast Mississippi. By midnight, heavier rain and embedded thunder will be spreading northward into the heart of our viewing area, and between then and early to mid afternoon on Thursday, waves of heavy rain and thunderstorms will continue at times across much of the area.
When all is said and done, a widespread 2 to 3 inches of rain can be expected across the area, with the potential for up to 4 to 5 inches of rain in some localized areas. Our high resolution Futurecast model shows several communities in the area getting 3 to 4 inches of rain.
The good news is that the widespread heavy rain will keep our temperatures rain-cooled and keep instability off to our south. For this reason, the Storm Prediction Center has the Level 1 of 5 risk of severe storms because of Beta's remnants off to our south, in central and southern Alabama. Especially for areas south of Birmingham, AL there may be an isolated spin-up tornado or two. For our viewing area, temperatures likely won't get out of the 60s on Thursday, and this rain-cooled and stable air will prevent a severe weather risk in our area. We can't rule out a 40 mph wind gust with a few of the storms though, but for a severe thunderstorm warning, wind gusts have to be 58 mph or greater. But you can sometimes get a tree blown down with 30-40 mph winds when heavy rain loosens the soil. The biggest threat for tonight and Thursday is definitely the potential for heavy rain and flash flooding across all of our viewing area.