Extreme Humidity, 3 Chances For Thunderstorms: Philly Area Forecast This Week

Crushing humidity stronger than anything the Philadelphia region has seen this year will envelop the area this week, causing the heat index to spike over 100 and bringing multiple days with risks of potentially severe storms.

Accuweather pointed to a high energy demand and risk of heat-related illnesses.

"Enthusiasts of summery weather will be happy, while those doing manual labor may struggle with a surge of heat and high humidity building across the eastern United States this week," Accuweather said. "The hot, moist air may fuel strong thunderstorms before the week's end."

The inclement weather was described by the National Weather Service as "scattered, hit or miss" storms. Their risk level remains level 1, or marginal, out of 5 on the agency's scale.

The humidity will first arrive on Wednesday, with the heat index spiking from 80 on Tuesday to 92 Wednesday. Some thunderstorms are possible from before 4 p.m. to 8 p.m., while rain is very likely, forecasters said.

Humidity will spike to 102 in Philadelphia on Thursday. Storms will again threaten in the afternoon and early evening, primarily after 2 p.m. and potentially continuing until 2 a.m. Anywhere from a quarter of an inch to half an inch of rain could fall, with higher amounts in thunderstorms.

It's a similar forecast for Friday, with the potential for storms lingering from 2 p.m. to 2 a.m., with the highest chance in the late afternoon and early evening. Friday's heat index will again reach 102, the National Weather Service said.

Damaging winds are the most likely severe impact from the storms, officials said.

Here's the full forecast for the coming week around the Philly area, according to the National Weather Service:

Tuesday
Mostly sunny, with a high near 83. Southwest wind 5 to 10 mph.

Tuesday Night
Partly cloudy, with a low around 65. South wind 5 to 10 mph.

Wednesday
Showers and thunderstorms likely, mainly before 4 p.m. Mostly cloudy, with a high near 86. South wind 5 to 10 mph. Chance of precipitation is 70 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Wednesday Night
Showers and thunderstorms likely, mainly before 8 p.m. Mostly cloudy, with a low around 70. South wind around 5 mph. Chance of precipitation is 60 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Thursday
A chance of showers and thunderstorms after 2 p.m. Mostly sunny, with a high near 94. West wind 5 to 10 mph. Chance of precipitation is 40 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Thursday Night
A chance of showers and thunderstorms before 2 a.m. Mostly cloudy, with a low around 73. Chance of precipitation is 40 percent. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Friday
A chance of showers after 2 p.m. Mostly sunny, with a high near 94. Chance of precipitation is 30 percent.

Friday Night
A chance of showers before 8 p.m., then a chance of showers and thunderstorms between 8 p.m. and 2 a.m. Mostly cloudy, with a low around 71. Chance of precipitation is 40 percent.

Saturday
Mostly sunny, with a high near 90.

Saturday Night
Mostly clear, with a low around 68.

Sunday
Mostly sunny, with a high near 91.

Sunday Night
Partly cloudy, with a low around 68.

Monday
A chance of showers and thunderstorms. Partly sunny, with a high near 87. Chance of precipitation is 40 percent.