People on Cape Cod are running and walking in the rain today in what may become dangerous thunder and lightning storms.
Severe thunderstorms will threaten part of the East Coast as well as the Tennessee Valley Friday. There is an elevated threat for blinding downpours with flash and urban flooding.
There is a threat of damaging wind and the possibility of a couple of brief tornadoes being produced by the strong storms. In this situation, a quick, spin-up tornado can be wrapped with rain and difficult to see.
There are two main areas at risk for damaging wind gusts and an isolated tornado Friday.
The first area stretches along the I-95 corridor from Massachusetts to North Carolina. This area encompasses the cities of Boston, New York, Baltimore, Washington, Richmond, Va., and Raleigh, N.C.
Severe thunderstorms will occur in part of the South. Thunderstorms will cluster from northern Mississippi to western Georgia.
In between, there will still be spotty strong to severe thunderstorms, just not as concentrated as that of parts of the Northeast and farther south and west.
Because of the high humidity, any of the storms have the potential to produce localized flooding.
Incidents of flash flooding were observed Thursday as storms rolled through the East, dropping several inches of rain in just a few hours. The worst of the flooding occurred along the I-80 corridor across Pennsylvania, forcing the closure of streets and highways as well as evacuations and water rescues.
Damaging wind gusts accompanied some of these storms with several reports of funnel clouds, although no tornadoes were confirmed.
Keep in mind while driving that a few inches of flowing water over roadways can move your car. If you come upon a flooded roadway, it is recommended that you avoid trying to drive through it.
Trees blown over by strong winds can divert water and make travel more difficult.
Severe thunderstorms will diminish across the East by the weekend, although the continued chance for torrential downpours will lead to additional flooding in areas already hit hard and can bring flooding to locations that have not yet experienced it with this weather pattern.
Story by AccuWeather.com Meteorologist Brian Lada.