A flash flood watch was in effect for Bergen, Essex, Hudson, Hunterdon, Mercer, Middlesex, Morris, Passaic, Somerset, Sussex, Union and Warren counties Thursday morning into Friday.
Severe thunderstorms with potential for isolated twisters were also possible, the National Weather Service says.
The main threat was expected midday Thursday into the early overnight hours, the NWS says.
Storms were, however, expected to move out quickly Friday.
Click here to follow Daily Voice Northern Valley and receive free news updates.