A very complex forecast with a lot of moving parts is setting up today, and tiny changes will have big impacts on our severe weather threat as we head through this afternoon and tonight. As of late morning, it was cloudy, with a shield of moderate to heavy rain over much of Northwest Alabama and Northeast Mississippi.
Warm, unstable air is located to our south this morning, but the heavy rain has limited its northward progression areas west of I-65 so far today. However, further east, unstable air is starting to lift northward a bit, and the atmosphere west of I-65 will start to destabilize once the heavy rain moves out later this afternoon. Where we stay mostly dry for the next few hours, the air will become unstable, and wind shear will increase, making the environment supportive of severe storms.
Forecast models are struggling with the fine details of this setup, so this may end up going one of a couple of ways today and tonight. The most aggressive models suggest unstable air rushes northward this afternoon, and by mid-afternoon, multiple clusters of severe storms move in from Mississippi, capable of destructive winds, hail, tornadoes, and flash flooding.
If this model has it right, then we’d have a busy day in the weather office, with lots of damaging wind, flooding, and a few tornadoes.
However, there’s plenty of reason to think we may miss out on the worst of this event, and have some strong storms, but not as significantly severe as some models suggest. If we remain more stable and the better upper-air support stays to our north, we might get through this with more heavy rain, and just a few instances of stronger wind.
The line between us getting a big severe weather day today and a lower-end event is razor-thin. It’s best to be prepared for a big day today, and hope for the best. Make sure you have multiple ways to receive warnings and know your severe weather safety plan.
Weekend Severe Weather Threat
Another cold front moves into the Southeast on Saturday, triggering another round of severe storms. This system appears to be much more potent than Wednesday’s, with much stronger upper-air support, and plenty of shear and unstable air to support significant severe weather across North Alabama and Southern-Middle Tennessee.
A strong squall line could move into Northwest Alabama and Southern Middle Tennessee as early as Midday Saturday, with the line of storms progressing eastward through the day and into Saturday night. These storms will be capable of destructive straight-line winds, hail, flash flooding, and tornadoes. We’ll continue to fine-tune the timing and threats these weekend storms will pose in the coming days, so be sure to check back in on the forecast often.