Timeline For Extreme PA Weather: Heat Wave, Storms This Week

PHILADELPHIA, PA - Three days of extreme heat and potential thunderstorms are in the forecast for the Philadelphia region. The National Weather Service has issued a heat advisory through 8 p.m. Wednesday. Expect heat index values of up to 104 degrees in the Philadelphia region during the heat wave.

Temperatures are expected to climb to as much as 10 degrees above normal.

The hottest days of the heat wave will likely be Monday and Tuesday, but the warmth is expected to linger through at least the middle part of the week, AccuWeather Meteorologist Matt Benz said.

The next three days will be hot and humid. Heat indices (apparent temperatures) will exceed 100 degrees in many areas during the afternoon hours. Take frequent breaks, drink plenty of fluids, and check on your neighbors and pets! #pawx #njwx #dewx #mdwx pic.twitter.com/yU8RaKetwU
— NWS Mount Holly (@NWS_MountHolly) June 28, 2021

Thunderstorms are also possible throughout the week, with chances of storms in the forecast from Tuesday through Friday.

Forecasters warn that the hot temperatures and high humidity may cause heat illnesses to occur.

Experts advise drinking plenty of fluids. Residents should stay in an air-conditioned room whenever possible and stay out of the sun. Young children and pets should never be left unattended in cars "under any circumstances," the National Weather Service said.

Those who work outside should take extra precautions and reschedule strenuous activities to early morning or evening.

Here is the forecast:

Today: Mostly sunny, with a high near 93. Heat index values as high as 100. Southwest wind around 10 mph.

Tonight: Mostly clear, with a low around 72. Southwest wind around 5 mph.

Tuesday: A slight chance of showers and thunderstorms after 2 p.m. Sunny, with a high near 95. Heat index values as high as 103. Southwest wind 5 to 10 mph. Chance of precipitation is 20 percent.

Tuesday Night: Partly cloudy, with a low around 74. Southwest wind around 5 mph.

Wednesday: A chance of showers and thunderstorms after 2 p.m. Some of the storms could produce heavy rain. Sunny, with a high near 96. Southwest 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: A chance of showers and thunderstorms. Some of the storms could produce heavy rain. Partly cloudy, with a low around 72. Chance of precipitation is 40 percent. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Thursday: A chance of showers, then showers and possibly a thunderstorm after 2 p.m. High near 89. Chance of precipitation is 80 percent.

Thursday Night: Showers and possibly a thunderstorm before 2 a.m., then a chance of showers. Low around 69. Chance of precipitation is 80 percent.

Friday: Showers likely, with thunderstorms also possible after 2 p.m. Mostly cloudy, with a high near 81. Chance of precipitation is 70 percent.