It’s still hot outside — a heat advisory is in effect for the western half of Tennessee today, but the eastern half will be quite warm as well, and we’re running about two degrees hotter than normal for the month of July — but changes appear to be in store.
In fact, it looks like we may not get out of the 70s here on the northern Cumberland Plateau for much of next week!
This cooldown has been showing up on models for sometime. I’ve been reticient to put too much faith in the pattern change, because our models haven’t behaved too well as of late. (Case in point: we expected some fairly substantial rainfall this week from the remnants of Tropical Storm Barry, and that simply didn’t pan out.) But as next week draws nearer, the cooldown continues to look more likely.
The pattern change will be ushered in by what should be a fairly wet weekend, with scattered to numerous thunderstorms late Saturday into Monday. After that, it looks like things will dry out as cooler weather settles in. While it isn’t a forecast, the current run of the GFS global model operated by the National Weather Service provides a glimpse at what temperatures could be like next week. It is projecting a high of 78 on Monday, a high of just 74 on Tuesday, and a high of 77 on Wednesday. After that, a warming trend begins, but we may not hit 80 again on Thursday. Nighttime lows could drop into the 50s Wednesday and Thursday mornings.
For whatever it’s worth, the NWS forecast is currently going a little above model guidance. Forecasters there are projecting high temperatures in the low 80s each day next week. That would still be much cooler than it’s going to be the next couple of days, when heat indexes will be in the 90s here on the plateau and perhaps even breaking triple digits in the valley around the greater Knoxville area.
For illustration purposes, here is what NOAA’s Climate Prediction Center is forecasting for Days 6-10 (July 23-27), in terms of temperature anomalies:
The CPC is actually showing a probability of cooler-than-average weather through the remainder of the month, but summer isn’t over by any means. August, as well as the early fall months, are currently projected to be warmer than normal.