We’ve had the hottest stretch in the Tennessee Valley over the last couple of weeks including several heat advisories. That’s about the change in just a few short days. A true cold front moves through the area on Friday bringing milder temperatures and drier air to our region. It will be a welcome relief as some of the hottest air on record has occurred in the latter part of July. The all-time record in Huntsville was set on July 29, 1930, with a high of 111°.
There is a look at the 850 millibar heights for Saturday morning. There are a couple of things to note on this map. First, notice the yellow and orange taking over Alabama and Tennessee. There is cooler air around 5000 feet. The darker red and maroon (hottest air) is shunted to the south and west. This translates to cooler temperatures at the surface. Opposed to the middle to upper 90s, we see upper 80s for highs this weekend. Secondly, the white flow lines show a “trough” along the east coast. It looks like an angled U” from New England to the gulf coast. When this pattern occurs, it’s not conducive for steamy temperatures. We need a ridge at the surface and aloft for the hottest temperatures. Here is a look at the cool down this weekend.
Interestingly enough, it’s been a little cooler the last three days of July in recent years with an exception of a couple of hot afternoons.
Last Three Years – July 29-31st:
- 2016 – 83°, 89°, and 88°
- 2015 – 100°, 89°, and 93°
- 2014 – 81°, 86°, and 85°
Enjoy this because August will likely rebound in the lower to middle 90s. We’ve had some hot September’s as well. October guarantees cooler temperatures with the potential for frost by Halloween. Hard to believe we are only three months away from the potential for a frost/freeze!