Severe thunderstorms re-firing from a prior derecho, will stretch from part of the Midwest to part of the mid-Atlantic into Wednesday night.
While the system is past its peak intensity, the threat of severe weather will reach from southeastern Missouri and southern Illinois to Kentucky, northern Tennessee, southern Indiana and southwestern Ohio Wednesday evening as individual storms strengthen.
The storms will bring a threat of damaging wind gusts, hail, flash flooding and frequent lightning, along with the chance of a few isolated tornadoes.
Downed trees, power outages, blocked roads, property damage and hazards to individuals may affect communities from Cape Girardeau, Missouri, to Louisville, Kentucky; Nashville, Tennessee; Cincinnati; Charleston, West Virginia and Roanoke, Virginia.
Part of the area can be hit with enough rain to cause flash, urban and small stream flooding.
During Wednesday night, the system will split into two parts. Locally heavy and gusty thunderstorms will shift southward across Tennessee, southern Virginia, northern and western North Carolina, northern Alabama and northern Georgia.
Drenching rain and risk of flash flooding will push eastward across southern Pennsylvania, northern West Virginia, northern Maryland, New Jersey, Delaware, northern Virginia and southeastern New York state.
Rain will soak southern New England Thursday morning.
Additional clusters of thunderstorms, severe weather and the potential for flooding will occur over parts of the Plains, Midwest and South later in the week and into the weekend.
Severe storms clustered into a fast-moving zone of high winds and heavy rain Tuesday, leaving a swath of wind damage from Nebraska to Missouri. The storm system has had a history of rainfall rates of 2 inches per hour and wind gusts to 60 mph.
This phenomenon is known as a derecho and traditionally brings extensive damage and risk to lives over a broad area.
There is a risk for damaging thunderstorms and travel disruptions even in the absence of the formation and persistence of a long-lived, single complex of severe thunderstorms.
This is one of several times a year when people in the alert area should pay very close attention to the weather.
Tropical Depression Seven strengthened into Tropical Storm Gaston during Monday night with another system attempting to form near the Caribbean.
Following a fall-like start to the week, warmth and humidity will build over the northeastern United States prior to the weekend.
A budding tropical disturbance has the potential to reach Florida with gusty winds, showers and thunderstorms during Sunday and Monday.
The return of warmer and more humid air will trigger another round of strong thunderstorms across the central United States this week.
Stargazers will want to dig out their binoculars and telescopes this weekend as Venus and Jupiter shine so close that they appear as one large, bright star in the evening sky.
Several days of intense heat will build across France this week with temperatures approaching 38 C (100 F) in many locations.
Denver, CO (1921)
2.20 inches of rain in 1 hour.
Chesapeake Bay Area (1933)
Hurricane - 6.39 inches of rain in Washington, D.C. Damage in Maryland close to $17 million. Tide 7 feet above normal flooded Norfolk, VA.
Dry thunderstorms ignited more than 100 fires in the Wenatchee and Okanogan National Forests.