Published June 11, 2013
There is a risk of thunderstorms with damaging winds and a few tornadoes from Wednesday night to Thursday night in parts of the mid-Atlantic and South.
Strong thunderstorms and localized flooding incidents are likely in portions of West Virginia, Virginia, Maryland, Pennsylvania, New York, New Jersey, North Carolina, South Carolina and Georgia as one or more complexes of thunderstorms roll in from the Midwest then turn southward over time.
The storm complexes bring a risk of 60-mph wind gusts, downed trees, sporadic power outages, minor property damage and flash flooding on an isolated basis.
However, a few of the storms could become intense with the risk of producing tornadoes and 80-mph wind gusts as well as large hail, torrential downpours and frequent lightning strikes. Communities hit by these storms could experience many downed trees, widespread power outages and more significant property damage.
At this time the area of greatest concern is taking aim from Harrisburg, Pa., Philadelphia, Washington, D.C., Baltimore and vicinity southeastward to Delmarva Peninsula, Richmond, Norfolk and southward into part of the Carolinas Thursday.
One or more complexes of storms will target portions the Ohio Valley. There is the risk of an intense, fast-moving storm complex, known as a derecho in part of this area, Wednesday into Wednesday night.
It is unclear at this time whether or not the storms in the East will be as organized as the storms in the Midwest. The meteorological form of the severe weather could range from widely separated severe thunderstorms yielding a tornado outbreak, to multiple squall lines to powerful thunderstorm complexes. However, the outcome in areas hit could be just as dramatic as a derecho and much more intense than your average thunderstorms.
Just north of the high wind risk area of the storms, a zone of thundery rain will occur with a risk of flash, urban and small stream flooding.
The heavy rain is likely to take a swipe over northern Pennsylvania, northern New Jersey, New York City and part of upstate New York state Wednesday night into Thursday and could slow travel along parts of I-80 and the Southern Tier Expressway.
A word of caution, however. If a thunderstorm complex fires farther north over the Midwest than expected, the risk of damaging winds would also be shifted farther north in the mid-Atlantic.
The storms are forecast to fire along the northern and eastern rim of building heat centered over the central Rockies and southern Plains this week.
The overall pattern fits in to the AccuWeather.com forecast for the summer of 2013, described earlier in May.