Sometimes forecast details are clear, and sometimes they are murky. This is one of those more ‘murky’ times! A slow-moving but potent Spring storm system moves out of Texas and Oklahoma Friday, and there is a significant risk of severe weather with that system west of Alabama.
That’s the only part of this that looks ‘clear’ right now because the storm system moves so slowly!
What’s most likely around here? Significant severe weather west of Alabama on Friday & Friday night consolidates into a wavy line of storms early Saturday. It slowly moves across North Alabama and Southern Tennessee through the day; a few storms in that first wave might be severe with strong winds, hail, and a low-end threat of tornadoes.
Rain continues throughout the day into Saturday night, and if big storms fire up closer to the Gulf Coast (as it looks like they probably will), we won’t see much more ‘stormy’ weather than just some rain and wind. If those storms don’t develop as expected, it could be rougher up this way Saturday afternoon and evening.
Why is it ‘murky?’ (Nerd alert – model talk) Model guidance only gets us so far. The American-run GFS has been the most consistent with the dynamics (the functional parts of the system that make it do what it does); the European, Canadian, and now NAM all have different ideas. For a crystal-clear forecast, you like to see at least some agreement in the guidance; there is very little at this point.
Using the GFS at face value, there is a chance of a few storms with strong winds and small hail: maybe a short-lived tornado if things come together just right. On the other hand, the way it brings in a load of rain ahead of the main dynamics that would force intense thunderstorms leads us to think – at least for now – that the greater threat may be south of the Tennessee Valley.
What could change? As mentioned before, this is not a very clear setup for severe weather in North Alabama; however, should the system slow down even more, then we could see the severe weather potential increase, If it moves a little faster, we may see the threat decrease.
Total rainfall through the weekend? Around 1” to 2” on average with a few spots getting a little more than 3 inches.