The National Weather Service said as much as 3 inches of rain could fall when thunderstorms move across the region Thursday afternoon and Thursday night.
The National Weather Service has issued a severe thunderstorm watch for 17 New Jersey counties and a series of flood advisories and flash flood warnings in several parts of the Garden State as well as New York City, saying as much as 3 inches of rain could fall when strong thunderstorms move across the region Thursday afternoon and Thursday evening.
As of 2 p.m., rain showers and some thunderstorms were moving through central Pennsylvania but had not yet made their way into New Jersey. That all changed after 3 p.m., when scattered thunderstorms began popping up in northern and central sections of the state.
Forecasters from the weather service say the storms will increase in intensity as they continue to develop Thursday evening.
Update: At about 4:45 p.m., the National Weather Service issued a severe thunderstorm warning for Middlesex and Somerset counties, as well as eastern Hunterdon, southeastern Morris, northwestern Mercer and northeastern Monmouth, effective until 5:45 p.m.
A severe thunderstorm was located near Whitehouse Station and Somerville, packing wind gusts as strong as 60 mph and moving east at about 30 mph, the weather service said. The storm was producing hail and frequent lightning.
Also, strong storms were moving through parts of Burlington, Mercer and Monmouth counties at about 5:15 p.m., packing winds up to 40 mph.
"Additional rounds of heavy rain producing thunderstorms are again possible tonight," the weather service's Upton, N.Y., office said in its flash flood watch. "Three inches or more of rain will be possible where the heaviest and most persistent storms occur, leading to flash flooding."
Heat warnings issued amid summer scorcher
A flash flood watch has been posted for the New Jersey counties of Bergen, Essex, Hudson, Passaic and Union, as well as New York City, Long Island, the lower Hudson Valley and southern Connecticut. It is effective from Thursday afternoon through 6 a.m. Friday.
A severe thunderstorm watch has been issued for Bergen, Essex, Hudson, Morris, Passaic, Sussex and Union counties, effective from 2 p.m. to 9 p.m. Thursday. The same watch also includes New York City and Long Island.
A severe thunderstorm watch has been issued for parts of CT, MA, NJ, NY until 9 PM EDT pic.twitter.com/ftxIsXNaLO
-- NWS New York NY (@NWSNewYorkNY) July 13, 2017
Storm updates:
- At about 3 p.m., the severe thunderstorm watch was expanded to include Burlington, Camden, Gloucester, Hunterdon, Mercer, Middlesex, Monmouth, Ocean, Somerset and Warren counties, effective through 9 p.m. Thursday.
- At about 3:30 p.m., a strong thunderstorm packing winds up to 40 mph was moving across parts of Mercer, Somerset, Middlesex and Monmouth counties, the National Weather Service reported. Torrential rain was falling in some of those areas, and there was a possibility of pea-sized hail.
- Another thunderstorm was moving through Sussex County and heading toward northern Passaic County at about 3:45 p.m., and a large batch of thunderstorms was moving through eastern Pennsylvania and taking aim at Warren and Hunterdon counties at about 4 p.m.
- Shortly after 4 p.m., a flood advisory was issued for Hunterdon, Morris, Somerset and Warren counties, along with south-central Sussex County and parts of eastern Pennsylvania because of heavy rain falling in those areas.
- Shortly after 5 p.m., a flood advisory was issued for Mercer and Middlesex counties, northern Burlington County, northwestern Camden County, central Monmouth and northwestern Ocean, effective through 8 p.m.
- At 5:30 p.m., a flash flood warning was issued for Middlesex and Monmouth counties, northern Burlington, central Mercer and northern Ocean, effective through 8:30 p.m., because of thunderstorm cells that were producing rainfall rates up to 2 inches per hour.
- A severe thunderstorm warning was issued, effective until 6:15 p.m., for the same areas covered in the flash flood warning.
Intense heat lingers
New Jersey is in the midst of its hottest day of the week, with temperatures reaching as high as 97 degrees in Toms River, 97 degrees at Atlantic City International Airport (an unofficial record for July 13), and 97 degrees in Cape May Court House, Oceanport and Seaside Heights, according to climate data from the National Weather Service and the New Jersey Weather & Climate Network at Rutgers University.
Making Thursday feel even more oppressive is the high humidity.
During the early afternoon, the heat index -- how hot it feels when the air temperature is combined with the relative humidity -- soared to 106 in Cherry Hill, 105 at Atlantic City Airport in Pomona, 105 in Millville, 105 in Upper Deerfield, 105 in West Deptford, 104 in Sicklerville, 104 in Wildwood and 102 in Toms River.
Live 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.