Midweek weather system approaches. Cooler to end the week. Trick-or-Treat weekend weather okay.
There's not a single cloud in immediate sight across the Tennessee Valley this afternoon! Beautiful cobalt blue October skies are in place. High pressure has temporarily settled into the area today as the clouds associated with the upper trough that brought our Monday morning cold front have shifted east of the area. However, this is just short-lived clearing as the next storm system is waiting in the wings off to the west.
Clear skies this evening will allow temperatures to drop rather quickly into the low to mid 50s right after sunset, but clouds will be on the increase overnight, and this will keep us from dropping too far as we head toward daybreak, with most of us sitting in the mid to upper 40s by daybreak on Wednesday morning. Winds become more southerly ahead of the approaching storm system on Wednesday, and with a few breaks in the clouds, that will allow afternoon temperatures to climb into the upper 60s and lower 70s.
The weather then gets ready to change in a big way as the big upper trough over the Plains and Rockies today and tonight shifts eastward toward the Southeast on Wednesday and then cuts off into an upper-level low over the Mississippi/Tennessee/Ohio Valleys going into Thursday.
Rain and a few rumbles of thunder move into the area during the late overnight Wednesday and into Thursday morning. Some of the rainfall could be heavy at times, but the risk of severe weather will be well south of us, down near the Gulf Coast. The frontal boundary moves through during the midday hours on Thursday, shifting the heavier rain to the east, but periods of showers will linger through Thursday night, Friday, and maybe even into Saturday morning as the cutoff upper low and associated surface low gradually shift across and out of the area.
The good news is that, despite showers lingering into Saturday morning, the forecast for actual trick-or-treating and other Halloween festivities on Saturday evening and into Sunday looks alright. It will be a bit chilly for trick-or-treaters, and they may want to carry a light jacket with their costumes, but weather looks dry both evenings.