Nasty storms incoming: Severe T-Storm Watch until 5pm Friday for NJ

This sticky spring day is about to turn stormy. A powerful squall line is charging eastward across Pennsylvania, and will arrive in New Jersey through the midday and afternoon hours on Friday.

In anticipation of potentially dangerous weather, the National Weather Service and Storm Prediction Center have issued a Severe Thunderstorm Watch for 14 of New Jersey's 21 counties until 5 p.m. Friday.

The watch specifically includes Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester, Hunterdon, Mercer, Middlesex, Monmouth, Ocean, Salem, Somerset, and Warren counties. (Although those nearby should not get complacent, as strong storms are still possible.)

A "watch" serves as a formal heads up that hazardous weather may occur, within a time frame of 6 to 8 hours. Severe weather threats include gusty winds, hail, and tornadoes. Flooding rains are also possible, along with frequent cloud-to-ground lightning.

Note: A watch is not a guarantee that storms will occur, nor that they will reach strong or severe limits.

If a "warning" is issued, seek shelter immediately inside a sturdy building, on the lowest level and away from windows. Never attempt to drive, walk, or swim through flooded areas.

These storms will push across New Jersey between about 11 a.m. and 4 p.m. Friday, generally from northwest to southeast. (So coastal and southern NJ will be the last locations in the state to see storms.)

Wind and downpours are the biggest threats here, although a tornado can not be ruled out. The "juiciest" and most humid air, most conducive to severe weather, is in South Jersey. (Dew points have risen to about 70 — that is steamy, summerlike air.)

Storms will exit the Garden State by late afternoon and early evening, leading to a quiet (although humid) overnight.

Saturday will be warm and humid, with one more round of thunderstorms likely. Those storms look spottier — less widespread — although potentially just as potent.

Cooler, drier air arrives on Sunday, providing a couple days of rain-free, storm-free weather.

Dan Zarrow is Chief Meteorologist for Townsquare Media New Jersey. Follow him on Facebook for the latest forecast and realtime weather updates.