Closings & Delays across the Tennessee Valley

More storms, less excessive heat through Friday!

Heavy, scattered afternoon thunderstorms Wednesday afternoon dropped a lot of rain over some spots and left others wanting more. The chance of daily thunderstorms is better than average for early August, but that still does not guarantee a widespread, everybody-gets-soaked rain through the end of the week.

More scattered storms develop Thursday and again Friday. The extra clouds and occasional whiffs of rain-cooled air help keep the heat down some for the rest of the week: highs in the middle and upper 80s on Thursday and Friday with a roughly 50-60 percent chance of at least 0.10” of rainfall at a given location in North Alabama and Southern Tennessee.  A few of the over-achieving storms could produce wind gusts over 50 miles per hour, produce temporary flash flooding, and bring intense, dangerous lightning.

Futurecast simulated radar for Thursday, August 9th

Why so spotty? Daily downpours this time of year aren’t driven by the same kinds of systems that bring more widespread, evenly-distributed rainfall at other times of year. These storms are driven mainly by daytime heating with a secondary ‘nudge’ from some weaker, often hardly noticeable disturbances and cool fronts.

The weaker the system, the less ‘organization’ you get in the rain pattern across the region.

Spotty storms like these are independent occurrences; they are made up of an updraft carrying hot, humid air from the surface high into the sky (fueling the storm) and a downdraft bringing rain-cooled air down from the cloud to the surface (like ‘exhaust’ from a storm). Since they’re individual units, they rain where they develop and rarely travel more than 10 to 20 miles from that point.

This kind of pattern lingers into the weekend, so expect more of the same on a daily basis: hit-or-miss, uneven, and unfair coverage of rainfall.

Weekend weather: While the chance of rain stays elevated from Friday into the weekend, it’s definitely not time to change or cancel any plans! There will be a chance of some downpours in the area whether you’re at Albertville’s Main Street Music Festival to back-to-school events around the region.

Here’s the take-away: it won’t rain all day, it won’t rain everywhere, and we only expect about 60 to 90 minutes’ worth of rain where it actually does rain on Friday, Saturday and Sunday.

Track heavy storms with WHNT.com’s Interactive Radar or swipe over to the radar feature on Live Alert 19!

Hotter with fewer storms next week: It’s August. There’s rarely any ‘cool’ weather, but we do have days that are hotter than others! The downward trend in the heat can only last until the storms thin out early next week; after that, we’re likely back in the mid-90s with a heat index over 100ºF by Tuesday, Wednesday and Thursday of next week.

Need some specifics about the weekend or next week? They’re always online at WHNT.com/Weather and in the “Daily Forecast” section on Live Alert 19!

-Jason
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