Some folks could be stranded, left in the dark or bailing water in the wake of heat-busting storms this weekend from the Midwest to the Northeast.
The weather pattern will shift enough to trim temperatures and humidity in many areas but is likely to set off heavy, gusty thunderstorms during the transition.
A severe weather outbreak is forecast from near the Great Lakes to across the St. Lawrence Valley bordering Canada and the United States Friday.
Some of the storms across north could be the most intense of the season for some locations with damaging wind gusts, large hail, torrential downpours and perhaps a few tornadoes.
While atmospheric conditions will change enough to somewhat limit the intensity of the storms farther south by Saturday, a few communities from the Ohio Valley to the mid-Atlantic and southern New England could still be hit hard.
The storms may localized downed trees and power outages, as well as flash and urban flooding.
Road and flight delays are likely as the storms roll through.
During Saturday afternoon and night, the surviving storms may stretch across a very heavily-populated area including from Cincinnati to Pittsburgh, Morgantown, W.Va., Baltimore, Wilmington, Del., Philadelphia, Trenton, N.J., New York City, Hartford, Conn., Providence, R.I., and Boston.
By Sunday, cooler and less humid air will filter across the Great Lakes and the Northeast.
However, the humidity will be slow to leave from the Ohio Valley to the southern mid-Atlantic and across the South. These areas could be unsettled Sunday with showers, locally strong thunderstorms and considerable cloudiness.
While extreme temperatures are not forecast to return quickly and we may not see duration heat experienced this week repeated this summer in the Northeast and around the Great Lakes, humidity levels are likely to creep back up next week.