Severe thunderstorms, evolving from a derecho, will stretch from part of the Midwest to part of the mid-Atlantic spanning Wednesday and Wednesday night.
On Wednesday, the threat of severe weather will reach from southeastern Missouri and southern Illinois to Kentucky, southern Indiana and southwestern Ohio.
The storms will bring a threat of widespread 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 St. Louis to Indianapolis, Louisville, Kentucky, and Cincinnati.
Part of the area can be hit with enough rain to cause flash, urban and small stream flooding.
During Wednesday night, the potential for severe thunderstorms, including flash flooding, will reach into West Virginia and Virginia.
According to AccuWeather Senior Meteorologist Kristina Pydynowski, severe storms forecast to cluster over central Plains Tuesday night may develop into a fast-moving zone of high winds and heavy rain, which will then continue to advance to the east-southeast on Wednesday.
This phenomenon is known as a derecho and traditionally brings extensive damage and risk to lives over a broad area.
Since the derecho has not formed yet, the exact path and longevity of this cluster of severe thunderstorms are uncertain. However, 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.