The National Weather Service has issued a tornado watch that stays in effect until 10 PM in 16 counties from southeast to northwest New Jersey.


Other counties in the advisory are Cape May, Atlantic, Camden, Cumberland, Gloucester, Hunterdon, Mercer, Middlesex, Monmouth, Morris, Salem, Somerset, Sussex and Warren.

A watch is essentially an indication that conditions leading to a tornado can develop. A warning is an indication that conditions exist, but haven't fallen into place. An alert means the likelihood of one.

NWS describes typical signs as dark, low-lying and possibly rotating clouds, a dark, almost-greenish sky, large hail and noise resembling a freight train.

Weather officials also recommend having an emergency kit and a family communication plan ready. If the watch evolves into a warning, it's a signal to take shelter immediately.