Saturday, June 25, 2016 9:33 PM

Substantial Cool-Down On The Way For Parts of the U.S. Next Week

Matthew Holliday

June has been hot and humid for many of us. There’s really no other way to put it. However, we have managed to get brief breaks in between the heat, and many of us will have a nice breather from the oppressive heat and humidity next week. In fact, there could be a couple cool downs in parts of the eastern U.S. leading up to July 4th, which I’ll discuss momentarily.

Before I get into the main discussion, check out the well-above average temperatures that most of the United States has had so far this month. In some places, temperatures have been as high as 10 degrees above average!

June 2016 Heat

A pretty potent disturbance is currently located over the Northern Plains, and its associated surface low pressure system is actually up in Canada. The cold front with this system extends across the Plains, and there is currently thunderstorm activity firing out along the front. The air mass ahead of this front is very hot and humid across much of the eastern U.S. There is a warm front associated with the low pressure system that extends from the Upper Midwest down to the northern Gulf coast states. Conditions are a little less humid above the warm front but not a substantial difference on either side of that boundary.

As the cold front sweeps across the eastern U.S. from early to mid week, a trough will build into the eastern U.S. while a ridge builds over the western U.S. This setup is your typical cool east, hot west pattern across the U.S.

The cold front will ultimately reach the northern Gulf coast states around mid-week and will stall out. The air mass behind the front will be substantially cooler and less humid. To give you an idea on locations, regions from the Upper Midwest through the Ohio Valley/Great Lakes and even the Tennessee Valley will reap the benefits of this cool-down the most. Other regions to get cooler conditions will be across the Mid-Atlantic and Northeast and as far west as the central and northern Plains. Highs in the 60s/70s and lows in the 50s/60s will be commonplace across most areas (early to mid-week depending on location) with temperatures probably in the 80s for highs across the Tennessee Valley (around mid-week) once the front moves through. In fact, I would not surprise for some of the northernmost areas closer to the Great Lakes and Upper-Midwest to have 40s at night and eventually into parts of the Northeast. Next week’s cooler temperatures will most likely be the first intrusion of cooler temperatures, followed by another cool-down behind that one at the beginning of July.

The below image shows you the projected departures from average temperatures for this upcoming Thursday morning from the European model:

cold front moving through eastern united states

Farther south from the Southern Plains across the Gulf coast states to the Southeast coast is where the forecast gets slightly trickier. As I’ve stated many times, these fronts tend to stall out across those regions, especially this time of year. I expect temperatures to cool off some across the parts of the northern Gulf coast states, but for the most part, temperatures will remain in the 90s and even close to 100 in places south of that line. In other words, those of you in these regions will have to go a bit farther north for the more noticeable cool-down. However, depending on the placement of the front later in the week, humidity levels could come down for some of you. Notice that I said for ‘some’ of you. Sorry, Florida!

Fortunately, there will be a good/better chance at getting rainfall across the Southeast/Tennessee Valley, where a pretty stout drought has developed over the last few months. Additional regions will have a shot at storms next week too, which will be discussed soon.

I’ll have more details on all of that tomorrow in your Sunday newsletter, but I just wanted to give everyone an overview of what we’ll be dealing with next week.