Early look 00 UTC

The 00 UTC NAM is coming in right now. No big changes…but new model run does take 60 dewpoints as far north as Nashville. This makes sense. Average wind speeds in the boundary layer (surface to about 4,000 feet) of 20-40 knots tomorrow mean it will only take air about 12 hours to get from the northern Gulf to BHM. Buoys indicate dew points south of Panama City in the lower 60s.

Tomorrow evening, wind fields increase even more as low-level jet moves in, which will set up a big threat for damaging straight-line winds, maybe over 70 mph in some spots. Very high confidence in severe storms with high winds. The instability is still the biggest question, at least as far as a tornado outbreak in Alabama. Temperatures could easily reach 80 tomorrow with some sunshine, and the models may be underestimating that, more than they are underestimating dew points. So, how much it cools off during the evening, how quickly the dewpoints rise, and how much warming actually occurs at 500 mb ahead of upper low, will have an impact. It’s hard to see how supercells with tornadoes don’t develop late tomorrow in Mississippi…we’ll just have to see if there is enough instability here for those to make it into Alabama, or if we mainly deal with only a damaging wind threat.

Tomorrow night will be active, so have your severe weather plan in place. I’ll have a more complete update with some graphics around 12 am, including the updated SPC outlook.

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