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.
Repeating and slow-moving storms will raise the risk of flash flooding and damaging winds over the northern and central High Plains into Thursday night.
Thunderstorms will bring the risk of severe weather to a portion of the mid-Atlantic states into Thursday night.
As July draws to a close, a storm system swinging up from the Deep South will bring downpours to the northeastern U.S. and break the back of an extended heat wave.
Rounds of showers and thunderstorms moving westward off the coast of Africa may pave the way for future tropical systems over the Atlantic Ocean in the weeks ahead.
Highs will run between 10 and 15 degrees Fahrenheit above average across much of the interior western United States into the upcoming weekend.
A budding tropical system threatens to bring flooding rain to the Philippines into this weekend with potential future impacts on China and Taiwan.
New England (1949)
Heat wave in New England; Greenville, RI hit 102 degrees.
Marquette, Il (1988)
99 degrees for a date record.
Hurricane Bertha formed 450 miles east of Jacksonville, FL. Maximum sustained winds of 75 mph with gusts to 90 mph.