Dangerous storms threaten to ruin outdoor plans and wreak havoc on the evening commute across the eastern Great Lakes and Northeast.
Very hot and muggy air will help to fuel the thunderstorms with temperatures climbing well into the 80s and 90s.
At least a couple of zones of nasty thunderstorms are expected to develop with the heating of the day encompassing areas from lower Michigan, Ohio, Pennsylvania and upstate New York to Virginia, the Delmarva, coastal New York, New Jersey and part of New England.
Some of the storms will become severe, providing the threat for damaging wind gusts and hail. In a couple of instances a tornado can be produced by the strongest storms.
Detroit, Cleveland, Buffalo, Pittsburgh, Philadelphia and perhaps New York City could all be in the path of the damaging storms.
The strongest storms can produce wind gusts to 65 mph which is more than enough to knock down tree limbs and power poles.
While damaging winds appear to be the biggest threat, there can be large hail and flash flooding.
If threatening weather approaches, be sure to have a secure indoor location to move to.
Heed any watches or warnings and as always, check back with the AccuWeather.com Severe Weather Center.
Strong thunderstorms will shift farther east Monday evening, bringing a damaging wind threat to Rochester, Burlington, and perhaps Montreal. However, as the night progresses, thunderstorms will lose their intensity thanks to loss of daytime heating.
Showers and thunderstorms will return to the Southwest late this week and could reach part of California.
A cold front swinging into the Northeast will bring the threat of severe weather to part of the region on Tuesday afternoon.
The southwest Gulf of Mexico has given birth to the Atlantic basin's fourth tropical storm of the season and will send torrential rain into northern Mexico.
Flooding is a concern across southwest Mexico through midweek as Norbert moves just offshore.
The Alaskan wood frog, which freezes itself during the harsh winter months, can remain in an extreme frozen state far longer than researchers originally thought.
An area of low pressure will bring a threat of heavy rain and flooding to parts of southern Europe through the middle of the week.
East Coast (1775)
Matecumbe Key, FL (1935)
Labor Day Hurricane hit Florida. Pressure at Matecumbe Key dipped to 26.35"/892.3 mb. Most intense hurricane ever to hit the U.S. with 200-mph wind. Tide of 15 feet; 408 dead.
Mecca, CA (1950)
126 degrees - highest ever for U.S. in Sept.