Heavy Rain, Thunderstorms Threaten Eastern PA Wednesday Evening

A rainstorm and possible thunderstorms will arrive in the greater Philadelphia area late Wednesday afternoon, forecasters said, bringing with it a rush of cool air that will bring the overnight temperatures into the upper 30s and low 40s throughout the week.

Up to an inch of rain is predicted to fall from around 5 p.m. Wednesday through early Thursday morning. Locally higher totals are possible within thunderstorms.

Thunderstorms are possible between 5 p.m. Wednesday and 2 a.m. Thursday.

Forecasters are calling this a "beneficial" rain due to the lingering drought conditions around the region.

Rain is most likely to be strongest in Philadelphia and the immediate suburbs at around 9 p.m.

Sunny and clear weather is expected the rest of the week, with highs persisting in the low to mid 60s. But nighttime temperatures will drop below normal.

"The chill arriving late this week will be driven by a large storm in the jet stream, rather than a sprawling area of Arctic high pressure," Accuweather said. "Systems like this tend to produce breezes and areas of low clouds that can linger after dark. The breeze helps prevent the coldest air from settling near the ground, while cloud cover acts like a blanket, limiting how much heat escapes."

Here's the full forecast for the greater Philadelphia area over the coming week:

Wednesday
A chance of showers and thunderstorms after 5 p.m. Mostly cloudy, with a high near 68. South wind 5 to 10 mph. Chance of precipitation is 30 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Wednesday Night
Showers and thunderstorms before 2 a.m., then a chance of showers. Low around 50. Southeast wind 5 to 10 mph. Chance of precipitation is 90 percent. New precipitation amounts between a quarter and half of an inch possible.

Thursday
Mostly sunny, with a high near 66. Northwest wind 10 to 15 mph.

Thursday Night
Mostly clear, with a low around 44. Northwest wind 5 to 10 mph.

Friday
Sunny, with a high near 63. West wind 5 to 10 mph, with gusts as high as 20 mph.

Friday Night
A slight chance of showers. Mostly cloudy, with a low around 43. Chance of precipitation is 20 percent.

Saturday
Partly sunny, with a high near 59.

Saturday Night
Mostly cloudy, with a low around 41.

Sunday
Mostly sunny, with a high near 61.

Sunday Night
Mostly clear, with a low around 45.

Monday
Mostly sunny, with a high near 67.

Monday Night
Partly cloudy, with a low around 48.

Tuesday
A chance of showers. Partly sunny, with a high near 71. Chance of precipitation is 30 percent.