BETHLEHEM, Pa. — After days of sweltering heat, the Lehigh Valley finally can expect a break, as a cold front will bring modest relief and cooler temperatures, forecasters say.
The front — moving northeast to southwest — is expected to push into the region throughout the day Thursday, stalling near or just southwest of the urban corridor for the afternoon before continuing its trek.
The boundary will divide the region into two distinct weather zones Thursday, the National Weather Service said in its latest forecast discussion.
Northeast of the front — areas including the Lehigh Valley, northwest New Jersey and the higher elevations of the Poconos — temperatures will start out warm before dipping closer to seasonal norms.
Highs will range from the mid- to upper 80s, with some spots staying in the 70s.
However, areas south and west of the front, including southern New Jersey and the Delmarva Peninsula, will be a bit different, the weather service said.
Temperatures in those areas are expected to climb into the low- to mid-90s, with heat index values between 95 and 105 degrees.
A heat advisory remains in effect for the Delmarva because of that “heat index gradient.”
Storms possible along the front
As the cold front advances, it’s expected to trigger scattered showers and thunderstorms, particularly along and just southwest of the boundary.
EPAWA meteorologist Bobby Martrich said storms will be most prevalent in central Pennsylvania because that’s where the boundary is going to be located.
The overall risk for severe weather is low for the Lehigh Valley, with the Storm Prediction Center placing the area at a marginal (1 of 5) risk of severe weather.
Forecasters note that multiple factors will limit the organization and severity of storms, with the main threat being isolated strong downdrafts and localized flash flooding, especially in areas that see repeated or slow-moving storms.
How it might affect the weekend
Martrich said the front will settle southwest of the region on Friday, bringing cooler temperatures, before returning northward as a warm front on Friday night, setting up a warmer weekend.
He said Saturday “doesn’t look too terrible,” with partly to mostly cloudy skies for much of the day before scattered late day thunderstorms are likely.
Sunday should see rain chances favoring areas well south of the Lehigh Valley.
“The second half of the weekend looks a lot better,” Martrich said. “It’s also a lot warmer, with temperatures in the upper 80s to near 90.”
