September-like cool air to plunge into midwestern, northeastern US

By Alex Sosnowski, AccuWeather senior meteorologist

June 23,2017, 8:36:06PM,EDT

 

Much cooler air with temperatures more typical of mid- to late September will sweep across the Great Lakes and Northeast this weekend into next week.

"Temperatures will stay below average from later this weekend through the middle of next week," according to AccuWeather Long-Range Meteorologist Max Vido.
Highs typically range from the middle 70s F to the middle 80s during late June. However, as the core of the cool air settles in, high temperatures will be held to the 60s over the upper Great Lakes, near 70 in parts of the Ohio Valley and the upper 70s across the Interstate 95 corridor of the mid-Atlantic.

Some areas from the Midwest to the central Appalachians may challenge record lows established as far back as the early 1900s.
Temperatures will dip into the 40s and lower 50s in much of the Midwest and the 50s to the lower 60s along the Atlantic Seaboard early next week.

Along with lower temperatures will be a substantial drop in humidity levels.
The less humid air will not only be felt as far to the east as the New England and mid-Atlantic coasts, but also into the Deep South.
The only real difference in how it will feel compared to September will be the strong June sunshine. Where and when the sun is out it will still feel warm, especially in your car.
Never leave children and pets unattended in a vehicle. Heat can build up to dangerous levels in a few minutes regardless of the outside temperature this time of the year.
This push of cooler and less humid air will end the risk of downpours in the Ohio Valley, central Appalachians and the Atlantic coast, following localized flooding attributed in part to Tropical Rainstorm Cindy.
Spotty showers and thunderstorms are likely to pop up around the Great Lakes, since the air aloft will be unusually chilly for June.

"The air may get cool enough to allow a couple of waterspouts to form over the Great Lakes from Sunday to Monday," Dombek said.
Small craft operators should be alert for rapidly changing weather conditions.
There are no signs of heat returning and staying for an extended period from the Upper Midwest to northern New England through the first part of July.
"Instead, it looks like the pattern will favor back-and-forth warm and cool days with only a brief spike in heat into the first week of July," Vido said.
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"It is possible temperature approach 90 for two to three days in parts of the Ohio Valley and the Interstate 95 corridor right at the end of June," Vido said.
Another sweep of cool air is possible by Independence Day.
The extensive swath of cool air with low humidity will translate to lower electricity usage when compared to average for late June and early July.
Many people will be able to turn off their household air conditioner and basement dehumidifier.
Most days along the Atlantic coast will still be warm enough for swimming and other summer outdoor activities. However, temperatures may dip low enough to hinder a few swimming days from the Great Lakes to the Appalachians.