September is North Alabama’s driest month of the year: usually. Huntsville’s average rainfall for the whole month is 3.49 inches; Huntsville International Airport recorded 4.72″ since Sunday. Scattered showers remain overnight, but rain slows to a drizzle (or nothing at all) overnight through Tuesday morning.
We have one more batch of showers and occasional storms coming before much cooler, drier air moves into the area.
All day rain on Tuesday? No. Everyone gets rain Tuesday? No again. Tuesday’s rain pattern mimics Monday: spotty, hit-or-miss, locally-heavy downpours. We avoid rain in the morning, but spotty shower and storms develop from lunchtime through early evening; the highest chance of rain (some heavy at times) comes overnight into Wednesday morning as a strong cold front passes.
First big-time Fall front
This thick, tropical humidity of late is not normal for September, but it is not unheard of here in the South! Strong cold fronts are also not common in the first part of the month, but we do start expecting more of a Fall-like feel on the downhill slide to October. That’s what we get starting Wednesday: which happens to be the Autumnal Equinox (Fall begins at 2:20 PM).
Rain sticks around for a while early Wednesday, but this strong cold front brings a huge push of cool, dry air for the rest of the week.
How cool are we talking here? Some communities in the higher terrain may have a hard time getting above 70ºF on Wednesday and Thursday. The usual cool spots around North Alabama and Southern Tennessee could drop as low as 44ºF to 49ºF by Thursday and Friday mornings.
Futurecast raw model output shows temperatures as cold as 41°F to 48°F by Friday morning. This may be a little too cool given the wet ground and season (record low for Friday is 41°F set in 1983), but it is not entirely impossible:
This pattern sets up a nice dry-out for us after recent excessive rainfall, and it means sweater weather for Football Friday this week! Temperatures for Friday evening games start in the mid-60s but drop to the 50s by the second half.
The weekend looks warm by day and cool at night: highs in the upper 70s/lower 80s, lows in the 50s, a mostly clear sky and a gentle west-northwest breeze.