AccuWeather reports after what will end up being one of the warmest weeks of the summer, much cooler air will sweep across the Atlantic Seaboard this weekend.
People having difficulties with the heat will get a break beginning this weekend.
The cool air will advance to the south and east spanning late this week over the Midwest, during the weekend along the northern Atlantic Seaboard and by early next week over the interior South.
The air originating from part of Canada that received snow on Wednesday will moderate on its travels into the United States. However, it will pack enough punch to slash temperatures by 10 to 15 degrees Fahrenheit, and even more in the Appalachians.
Instead of highs well into the 80s and 90s, highs will be the 70s to lower 80s. Instead of nighttime lows in the upper 60s and lower 70s, temperatures will dip into the 40s in the mountains and the upper 50s to lower 60s in some cities and most suburbs.
According to AccuWeather Senior Meteorologist Dave Dombek, "The air coming in this weekend into early next week will be about average for the date."
"Likewise, the weather pattern by early next week will be more typical of September, rather than the July pattern that we have now," Mr. Dombek said.
The front associated with the cool air will be preceded and accompanied by drenching showers and thunderstorms.
Depending on the time of the day the storms occur, some communities could be hit with flash flooding and strong wind gusts. The most likely time for heavy, gusty and locally severe storms would be from the early afternoon to the evening hours.
While portions of the interior South will cool off by way of clouds, showers and thunderstorms, humidity levels may be more sluggish to drop off.
The cool air will stick around into the the first part of next week, before temperatures rebound once again in the Northeast.
Many cities in the Northeast are falling below the normal number of 90-degree days for the season. For instance, Pittsburgh has not hit 90 F yet this year.
"If Pittsburgh fails to hit 90 degrees this Friday, the city is unlikely to hit 90 for the balance of the year, looking at the upcoming weather patterns," Mr. Dombek said.
How high temperatures climb during the middle part of next week in the East will depend on the amount of sunshine versus clouds and showers.
A much more robust push of cool air will follow.
According to AccuWeather Lead Long-Range Forecaster Paul Pastelok, "A very impressive push of air is forecast to move in during the middle of September that has the potential to bring some frost to the coldest interior locations of the Northeast and parts of the Midwest."
Mr. Pastelok stated that the mid-month air will become surprisingly chilly over the northern Plains and Upper Midwest.