Late-Week Break From Brutal Southern Heat Is Coming

Tom Moore
Published: September 27, 2016
Many cities across the South experienced one of the hottest climatological summers on record (June through August), and the heat has extended through September.
But at long last, there is some relief ahead as cooler and drier air invades the region later this week.
(MORE: 'Cut-Off' Low to Bring Persistent Clouds, Rain to the Northeast)

Brutal Southern Heat

Several Southern cities recorded one of their top two hottest summers on record, and the heat continued in September.
(Southeast Regional Climate Center)

A significant number of Southern cities experienced one of their three hottest climatological summers on record. For locations like Charleston, South Carolina, New Orleans and Tallahassee, it was the hottest summer since records began.
This excessive heat, with high humidity levels, has lasted through September. Meridian, Mississippi, just recorded a record high on five consecutive days. Their high temperature of 101 degrees on Sept. 24 was the latest 100-degree day on record.
Atlanta has recorded 87 days with a high temperature of 90 degrees or higher this year. The only two years that logged more were in 1980 and 2011 (90 days). The average number per year there is 36.
Interestingly enough, in 1967, Atlanta only recorded 2 days with a high of 90 degrees or greater.
(MORE: Summer 2016 Was One of the Hottest on Record In Lower 48 States, NOAA Says)

Cooldown Timing and Info

Forecast High Temperatures

A cold front, the leading edge of cooler and drier air, will push down into the South on Wednesday night and Thursday.
The temperature change will be quite noticeable for some areas by early Thursday. Highs Thursday will be in the 70s from Arkansas and Tennessee to northern Alabama, northern Georgia and the western Carolinas.
By Friday morning, you'll probably need a light jacket as lows dip into the 50s over a large portion of the region. Some higher elevations will see lows down into the 40s.
On Friday, cities along the Gulf Coast and Southeast Coast will experience a drop in temperature and humidity levels. The front will also make it into northern Florida, making it the first frontal passage of the fall season.
This pleasant change will continue into the weekend, with only slight warming on Sunday.

Forecast Low Temperatures

(MORE: August 2016 Global Temperatures Set 16th Straight Monthly Record)

Setup For a Cool Change

A "cut-off" low aloft will send cool and dry air into the South later this week.

Over the past few months, a ridge of high pressure aloft (bulge in the jet stream) has been the prevailing pattern across the South.
Later this week, a "cut-off" low – low pressure aloft that separates from the main jet stream – will set up from the Ohio Valley to the mid-Atlantic region by Thursday, and it will be around for a while.
Cool and dry air will move around the low and into the South. This will allow high temperatures to be at their lowest levels in months for many locations.
For example, the last time Atlanta recorded a high below 75 degrees was on May 20.
You might want to dig out a light jacket or a sweater with early morning lows in the 50s widespread across the region.
MORE: Fall In Every State