WHNT Weather

Cooler Temps and Some Good Rain

Posted on: 9:59 pm, July 6, 2012, by Jason Simpson, updated on: 10:00pm, July 6, 2012

This is the moment we have all been waiting for: the heat wave ends this weekend!

Temperatures will be trending down through the weekend, but we won’t declare the heat wave “gone” until temperatures fall back below the seasonal average for early to mid-July: 91 degrees for a high, 70 degrees for a low. Saturday will still have upper 90s and lower 100s in the middle of the afternoon, but the over-all trend is for more rain/storms and falling temperatures.

The persistent hot, dry weather caused by a strong ridge over the Central and Eastern United States is weakening and splitting; part of the hot air mass is sliding off the East Coast, and the other part is shifting west over the Rockies toward the West Coast. In between, a northwest flow and a dip in the jet stream will allow for some cooler air and better rain chances next week.

In fact, a weak cool front will blow into Middle Tennessee by Monday, and it will slowly move south into the Tennessee Valley of North Alabama by midweek. It will hang around the South for several days next week, and that’s a good thing for a region in need of rain. Stalled fronts provide convergence, which is a way to dynamically force rain and storms to develop. The more we can force rain to develop here with that front, the more it will help with drought conditions which have worsened into the “severe” category for much of North Alabama and Middle Tennessee this past week.

Rainfall will be greatest in Tennessee through the next five days, but even some of us in North Alabama will get more than an inch spread out over the time period. This forecast graphic from the Hydrometeorological Prediction Center shows accumulated rainfall over a 5-day period. It won’t all come down at one time, and that’s a good thing!