Heat to rebound in Northeast, following current humidity lull

A back-and-forth pattern of cool versus hot and steamy versus less humid will set up into this weekend, but cooler air or seasonable conditions may win out over the next several weeks.

After a stretch of lower humidity and noticeably cooler air into midweek, a bubble of heat will break off from a searing heat dome over the middle of the United States later this week, AccuWeather meteorologists say.

The current comfortable conditions will be favorable for anyone with outdoor plans or work, so be sure to take advantage before big heat returns.

Along with the big slash in humidity will come a cut in temperatures, especially at night. The sun will tend to go to work during the day, but the air will regain its origin from central Canada at night. Temperatures dipped into the 60s in New York City and Philadelphia, and into the mid-30s in some of the chilly spots over the Northeast's interior! Washington, D.C., bottomed out at 70 Tuesday morning.

Summer swelter to return

Over the next several days, a heat dome with highs in the 90s to low 100s will build over the middle of the Great Plains and the Mississippi Valley.

A piece of that heat dome will break off and lunge east later this week.

"The late-week scorcher heading into the East will be a quick whiplash," AccuWeather Senior Meteorologist Chad Merrill said. "The timing is in sync with the late-June surge in temperatures, but this one won’t last nearly as long."

Detroit will jump well into the 90s Thursday. Philadelphia will leap into the mid- and upper 90s Friday and Saturday with RealFeel® temperatures in the lower 100s. Some daily record highs will be challenged even though this is typically the hottest part of the year. Overnight temperatures won’t offer any relief, they'll be in the mid-70s to lower 80s.

A cool front looks to squash the heat in New England and part of the mid-Atlantic by Sunday.

"While the Mid-Atlantic and Northeast have been no stranger to high humidity this summer, the mid-90s have only made an appearance once this month in Philadelphia," Merril said. "Detroit has only reached 92 degrees this month. New York City will reach well into the 90s Friday and Saturday, following only three days with highs in the 90s earlier this month. So the short, hot and humid spell will be significant."

That two-day stretch of hot and humid conditions will occur as the jet stream moves prior to discharging more cool air, bringing lower humidity later in the month as a pattern favoring a lower number of hot and steamy days evolves.

Just like what ended the heat wave from late June, a cool front will drop this weekend. Similar to late June, the cool push will arrive from the northeast and north, rather than the more common route for cool fronts from the west and northwest.

For this weekend into early next week, how far to the west and southwest the cooler air can travel is still uncertain. However, a southward plunge in the jet stream accompanying the cool push may give it more south and west momentum than late June.

Temperatures may be slashed by 15-30 degrees in the wake of the front later this upcoming weekend. Highs in the 90s will be replaced with highs in the 80s and even the 70s.

In the pattern for the next three to four weeks, as a rough guide, the number of days with near to below historical average temperatures and humidity levels may outweigh the hot and humid days by a margin of two out of three days in the Northeast.

As each wave of cooler and less humid air collides with hot and humid air, rounds of thunderstorms are in store. Some of the storms will be severe.

Want next-level safety, ad-free? Unlock advanced, hyperlocal severe weather alerts when you subscribe to Premium+ on the AccuWeather app. AccuWeather Alerts™ are prompted by our expert meteorologists who monitor and analyze dangerous weather risks 24/7 to keep you and your family safer.

Report a Typo