Late Summer Heat Will Continue Next Week Across the South and East

Tom Moore
Published: September 17,2016
It's been a long, hot summer across the eastern U.S. and significant relief is not arriving anytime soon.
For many cities across the eastern U.S., this was one of the hottest meteorological summers (June-July-August) on record. This trend has continued through the first half of September and it doesn't appear that there will be any changes through next week.
Temperatures will be on the increase into early next week for the eastern two-thirds of the country. Daily highs will range up to 10 to 15 degrees above average through mid-week.

Forecast Highs

Timeline

Monday: The heat will start kicking into high gear across most of the U.S. including portions of the Southwest, South, East, and Midwest.
(MORE: Summer 2016 Was One of the Hottest on Record in the Lower 48 States, Says NOAA)
Tuesday: The heat will shift out of the west, but the central and eastern portion of the country will stay warmer than normal.
Midweek: The forecast through next week is for unseasonable warmth to continue across the East. Many cities will see high temperatures from 5 to 10 degrees above average at times.

Next Week's Forecast For Eastern Cities

Long Term: According to NOAA's Climate Prediction Center, there is a high probability for above average temperatures across the eastern U.S. in the next 6-10 days ahead (Sept. 22-26).

How Warm Have We Been?

Here are some examples of eastern cities indicating their average temperature this September (through Sept. 16) and number of degrees above average.
Some locations are running 4 degrees or more above average for September and there is nothing to indicate that these values will be dropping anytime soon.

City	Average Temperature (F)	Degrees (F) Above Average
Hartford	70.8	4.1
New York	74.7	4.2
Washington, D.C.	77.6	5.5
Raleigh	77.6	3.3
Atlanta	79.9	4.1

(MORE: La Niña Likely to Be a No Show This Fall and Winter)

Setup For Prolonged Heat

A persistent high pressure ridge (bulge in the jet stream) has kept temperatures well above average across the eastern U.S.

For the past few months, there has been a persistent high pressure ridge (bulge in the jet stream) across much of the eastern U.S.
During these periods the air sinks and warms, allowing temperatures to climb.
Humidity levels have also been quite high and the increased moisture traps the heat of the day.
As a result, much of the heat isn't allowed to escape into the atmosphere and that allows overnight temperatures to remain elevated.
This general pattern is likely to persist for awhile.
There are some computer models that indicate cooler conditions are possible across the East toward the end of the month.
MORE: Warm Weather Fun