For the majority of us, it has been a mainly overcast and dreary Monday, although there have been a few peaks of sun from time to time. Along with the clouds, there have been some isolated heavier showers over northwest Alabama earlier today, but most of them have faded for now. This is just a lull in the action before more widespread and heavier rain affects the area over the next few days.
Our high-resolution Baron Futurecast model shows the remaining few afternoon showers dying away toward sunset. From there, we stay mostly cloudy during the overnight, and there may even be some patchy fog overnight and toward daybreak on Tuesday. Morning lows bottom out in the low to mid 60s areawide. Heavier showers start to move northward out of central Alabama into some of our southern counties as early as daybreak, and these shift northward through the morning and midday hours. Other scattered heavy showers and storms look to develop through the afternoon and then increase in coverage going into the evening.
All this activity is in response to an upper-level low that is digging down into the Mid South today and cuts off and stalls out over the area for the next few days. Deep southerly flow on the east side of the upper low will promote periods of locally heavy rain through at least midweek. Futurecast suggests rain totals of 1 to 2 inches look likely on a widespread basis, with locally heavier amounts very possible, especially closer to some of our I-65 area counties. Any training heavier showers or storms elsewhere may also produce heavier rain totals in excess of 2 inches though. There is a Flash Flood Watch in place because of this, all the way through 1:00 AM Thursday, for all of our north Alabama viewing area counties. I would not be surprised if this is expanded up into portions of middle Tennessee with time.
This upper low stays stalled near the area through at least Wednesday, with rounds of heavy rain and storms likely. It gradually begins to lift to our north on Thursday, with drier air aloft moving in and the remnant surface boundary pushing off to our east. This will allow showers to become much more isolated, and by Friday and the weekend, we look to return to partly cloudy or even mostly sunny skies. Afternoon highs through Thursday look to stay in the mid 70s with the increased cloud cover and rain around, and then we warm into the upper 70s to near 80 from Friday into the weekend and sunshine returns to the area.