Dangerous flash flooding will threaten the I-95 corridor Wednesday night, especially from New York City to Washington, D.C.
Heavy rain will continue to inundate the eastern mid-Atlantic into Wednesday night, pushing streams out of their banks and covering streets in perhaps feet of water.
"The main threat in the Northeast will be from life-threatening flash flooding," said Northeast Weather Expert Dave Dombek.
Some areas will receive more than 4 inches of rain, some in a quick amount of time.
Enough rain and poor visibility can occur to disrupt flights at major airports from Washington, D.C., to Philadelphia, New York City and Boston into Wednesday night.
"A few of the storms will also bring the potential for strong wind gusts and large hail, while a handful of the smallest storms could produce a brief tornado," Dombek said.
However, the highest risk for severe weather will be across the Southeast.
Travel along stretches of I-40, I-70, I-80, I-81 and I-95 could be hazardous at times due to gusty storms and areas of blinding, heavy rain.
A nearly stationary storm system over the Upper Midwest will continue to push warm, moist air across the Southeastern states and will begin to push warm, moist air across the mid-Atlantic.
The threat of heavy, violent thunderstorms into Wednesday evening will span from northern Florida to southeastern Georgia, coastal South Carolina, eastern North Carolina, central and eastern Virginia and central and lower Maryland.
Severe weather will becoming increasingly isolated into Wednesday night though.
Part of the northern Florida Panhandle was overwhelmed with heavy rainfall Tuesday night. Portions of the Pensacola, Fla., area received over a foot of rain which caused flooding.
For some storm-weary people in the South, this will be the second or third day in a row with the potential for damaging thunderstorms.
"According to Southern Weather Expert Dan Kottlowski, "The strongest storms that erupt in portions of Virginia, the Carolinas and southeastern Georgia will bring damaging winds, large hail and isolated tornadoes."
The number of storms will be decidedly less numerous and less intense over much of Alabama, Tennessee and Mississippi. Much of this area may have no storms at all.
During Thursday into Saturday, the large storm stalled over the Midwest is forecast to weaken gradually and lift northward into Canada.
However, this slow process may allow another round of thunderstorms to fire right along the Atlantic Seaboard on Thursday from New England to Florida. Should a disturbance rotate in during the afternoon and evening hours, the thunderstorms could become locally severe.
Chilly showers over the Midwest are forecast to become less extensive moving forward into the weekend as the old storm diminishes. There is just the chance of a brief shower for Derby Day at Churchill Downs.
Content contributed by AccuWeather.com Meteorologist Andy Mussoline
Another round of rain is expected to move through the Carolinas on Saturday, which may lead to rises on some small streams and creeks.
A strengthening storm system will bring the threat for flooding, mudslides and severe thunderstorms to areas from Italy into the Balkans later Friday into the weekend.
Winter will kick off with mild weather in the Northeast and mid-Atlantic as an intensifying El Nino influences the weather pattern across the country.
A "blob" of abnormally cold water in the North Atlantic, located near Greenland, has the potential to put enough drag on the ocean current to impact weather conditions in the years to come.
“It was by far the most intimidating natural disaster I have ever chased,” Storm Chaser and Extreme Meteorologist Reed Timmer said of the historic flooding in South Carolina.
A fall-like weekend is in store for the Northeast, after rain and thunderstorms will dampen the region on Friday.
New England (1804)
Extraordinary "Snow Hurricane" - snow mixed with heavy rains from Washington, D.C. on north - heavy snow in interior New England. Up to 2 feet in Green Mountains of Vermont.
A few snow flakes in Philadelphia, PA (trace). Also a trace of snow in Baltimore, MD.
Damaging hailstorms - $7.5 million loss to crops.