A Taste of Autumn Arrives This Weekend, and So Is a Flooding Risk

The forecast for the Midwest and the interior Northeast is a double-edged sword. While relief from the heat is on the way, the atmospheric conditions will also support gusty thunderstorms and heavy rain capable of triggering flash flooding.

Cooler Air Moving Down from Canada

There is good news for millions of Americans tired of the heat. A surge of Canadian air will bring cooler temperatures this weekend to the Great Lakes, the central and northern Appalachians, and beyond. However, the change in the pattern will also spark drenching rain and the threat of severe weather.

The cooler and less humid conditions have already begun to spread to some areas of the Great Lakes and the Northeast. Highs in the upper 80s will swap out with readings that top out in the 70s to low 80s. Areas that see clear skies after the sun goes down could see overnight lows that dive as low as the 40s, bringing a true taste of fall to the northernmost areas of the U.S.

How far the jet stream dips will influence how far south the cooler and less humid air is able to infiltrate. A strong and rounded jet stream dip would send the cooler conditions offshore and into the Southeast. Conversely, a dip located farther inland would allow the warm and moist air to hang on throughout the populated Interstate 95 corridor.

What forecasters are certain about is that the break from the heat and humidity will be the main weather headline for the Great Lakes and the interior portions of the Northeast this weekend. The surge of cooler air will slowly push to the southeast as the weekend progresses.