The watch, effective through midnight, was issued as strong thunderstorms have been sweeping across areas south and west of New Jersey. Those storm cells, along with scattered rain showers, could dump as much as 1 inch of rain per hour, posing a threat of flash flooding, forecasters said.

At 5:41 p.m. on Friday, the National Weather Service released an updated tornado watch in effect until Saturday at midnight for Adams, Lancaster and York counties.