Tornado Watch Issued for Region

The Nation Weather Service has issued a tornado watch for 12 New Jersey counties, including Mercer and Middlesex, through tonight at 8 p.m.

Strong thunderstorms could develop during the late afternoon and evening hours, producing damaging wind gusts, large hail and a possible tornado, the NWS said.

The NWS said storms could bring winds of up to 70 m.p.h. with hail up to 2 inches in diameter for some areas.  The storm could also bring dangerous lightning strikes, according to the NWS.

"A tornado watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area," the NWS said.  "Persons in these areas should be on the lookout threatening weather conditions and listen for later statements and possible warnings."

The NWS predicts scattered thunderstorms in Vermont, New York and Pennsylvania will intensify and pass over New Jersey, Pennsylvania and New York this afternoon. The storms are due to “a very unstable air mass” that has developed across that region, the NWS reports. Taking into account other weather conditions, the NWS says the air mass “will pose a risk of supercell storms capable of large hail... damaging winds... and isolated tornadoes.”

The other states in the watch area are Connecticut, Massachusetts, Maine (western), New Hampshire, New York (southeast), Pennsylvania (southeast) and Rhode Island, as well as waters off the Atlantic Coast.

The NWS provided the following table for the likelihood of various conditions throughout the tornado watch area:

Note: Under the Enhanced Fujita Scale for estimating the danger of a tornado, an EF2 tornado is considered one that can seriously damage one-to-two-family houses.