An unusually strong low pressure for this time of year will spark powerful storms across much of the East into Friday night.
Storms have already produced torrential downpours this morning across much of Ohio, Pennsylvania, New York and Virginia. More of the same is on the way as well as the potential for damaging wind, hail and a couple of tornadoes.
Cities targeted include New York City, Philadelphia, Baltimore, Washington, D.C., Harrisburg, Allentown, Richmond, Virginia Beach, Raleigh and Columbia.
The most potent storms will explode this afternoon as the low pressure heads toward the area and strengthens, feeding off of tropical-like humidity.
Damaging blasts of wind, hail larger than quarters, and drenching downpours are all possible as rounds of slow-moving storms track east.
According to Severe Weather Expert Henry Margustiy, "An upper level disturbance lifting northward across Long Island and into central and eastern New England has the potential to produce a couple of tornadoes during the afternoon and early evening."
Blinding rain from time to time will cause plenty of travel headaches for motorists on major interstates. I-95, I-81, and I-80 are all in the crosshairs. Conditions will be just as bad on the New York Thruway and the Massachusetts, New Jersey and Pennsylvania turnpikes.
If you'll be traveling to or from area airports into Friday night, don't expect anything better, as locally severe storms threaten to cause plenty of flight delays.
Be alert for rapidly changing weather conditions and heed any watches or warnings that may be issued. Remember, if a warning is issued, this means a dangerous thunderstorm is imminent and you should take shelter immediately.
Be sure to stay with us at AccuWeather.com for all the latest details on this impending severe weather event.
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.
Mecca, CA (1950)
126 degrees - highest ever for U.S. in Sept.
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.