N.J. weather: Tornado watch issued for 10 counties as dangerous thunderstorms sweep through state

The National Weather Service has issued a tornado watch for 10 New Jersey counties, saying conditions are ripe for the development of isolated tornadoes as strong thunderstorms sweep through the state Tuesday evening and into the night.

The tornado watch is in effect until 10 p.m. and covers Burlington, Camden, Gloucester, Hunterdon, Mercer and Warren counties. Nearly all of Pennsylvania is also included in the watch.

Update 5:45 p.m.: The tornado watch has been expanded to include four more counties in New Jersey: Atlantic, Cape May, Cumberland and Salem.

Although a watch is not as urgent as a warning, the weather service says atmospheric conditions are conducive for small tornadoes to form. If any funnel clouds are spotted, or if forecasters notice rotating winds on weather radar, the watch will likely be upgraded to a tornado warning.

If a warning is issued, residents should take immediate cover to protect themselves from injury.

The National Weather Service offers these safety tips to follow if a tornado warning is issued:

If you are at home

— Go to your basement and hide under something sturdy, like a work bench or a heavy table, or cover yourself with a mattress or sleeping bag.

— If there is no basement in your home, go to the lowest floor, a small center room like a bathroom or closet, under a stairwell, or in an interior hallway with no windows.

— Avoid windows.

— If you are in a mobile home, get out and find a permanent structure until the tornado passes.

If you are at work or in another building

— Get away from any windows.

— Go to an enclosed area in the center of the building and stay as low as possible, away from glass.

— Crouch down and cover your head.

— Stay off elevators, because power can be knocked out.

Current weather radar

Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com. Follow him on Twitter @LensReality or like him on Facebook. Find NJ.com on Facebook.