Strong storms could produce small hail and frequent lightning Thursday afternoon, forecasters said.
With heavy rain showers continuing to push their way up from the south and across from the west, the National Weather Service has issued a severe thunderstorm watch for most of southern New Jersey.
The watch is effective through 5 p.m. Thursday.
At about 1 p.m., radar indicated a line of strong thunderstorms in Maryland moving northeast at 60 mph, heading toward southwestern sections of New Jersey, the National Weather Service said in a special weather statement.
Those storms could produce wind gusts as strong as 50 mph, along with pea-size hail and frequent cloud-to-ground lightning, the weather service said.
"Torrential rainfall is also occurring with these storms, and may cause localized flooding. Do not drive your vehicle through flooded roadways," the weather service said in its weather statement.
Vote for your favorite TV weather forecaster
Most of New Jersey received only light rain showers Thursday morning, but moderate to heavy showers are still expected to move across the state Thursday afternoon and evening.
At about 2 p.m., strong thunderstorms were moving toward central New Jersey. Those are expected to affect parts of Hunterdon, Mercer, Middlesex, Monmouth, Morris, Ocean and Somerset counties, the weather service said.
The severe thunderstorm watch is in effect in Atlantic, Burlington, Camden, Cape May, Cumberland, Gloucester and Salem counties. The watch also covers Bucks, Chester, Delaware, Montgomery and Philadelphia counties in eastern Pennsylvania.
Hail and wind reports
The National Weather Service reported quarter-inch hail in Washington Township in Gloucester County at about 1:35 p.m., along with wind gusts of 41 mph in Cape May and 40 mph in Ocean City between 2:35 p.m. and 2:45 p.m.
No warnings at the moment, but lots of heavy rain and lightning with these storms sweeping across South Jersey. Brisk winds too. pic.twitter.com/Hk3nIweIHm
-- Dan Skeldon (@ACPressSkeldon) April 6, 2017
New flood advisories
The National Weather Service has issued a flood advisory for Middlesex, Monmouth and Ocean counties, as well as eastern Morris County, effective until 8 p.m., because of the moderate to heavy rain that has been falling in those areas.
Flooding is expected in urban areas, along with streets that are low lying or have poor drainage, the weather service said. A flood advisory means rivers or streams have elevated water levels or ponding of water is already occurring or is imminent.
Len Melisurgo may be reached at LMelisurgo@njadvancemedia.com. Follow him on Twitter @LensReality or like him on Facebook. Find NJ.com on Facebook.