Severe Thunderstorm Watches Issued With 70 MPH Winds In PA Forecast

PENNSYLVANIA — Thunderstorms are arriving in eastern Pennsylvania, bringing the possibility of rain, damaging winds and even hail as the mercury rises to the mid-90s on Thursday.

The storms will start around 2 p.m. and last through Thursday night, the National Weather Service said. The primary threats to the Keystone State will be damaging wind gusts between 60 and 70 mph and localized flash flooding. There is a smaller chance of hail, the weather service added.

The risk of flash flooding is isolated, though regions where downpours may last for a few hours or repeat multiple times from Thursday to Thursday night may see disastrous flash flooding similar to the flooding seen earlier in July, AccuWeather Meteorologist Brandon Buckingham said.

As of 3:30 p.m. the following Pennsylvania counties are under a severe thunderstorm watch until 11 p.m. Thursday, per the NWS:

• Adams
• Bedford
• Berks
• Bucks
• Carbon
• Chester
• Cumberland
• Dauphin
• Delaware
• Franklin
• Fulton
• Lancaster
• Lebanon
• Lehigh
• Monroe
• Montgomery
• Northampton
• Perry
• Philadelphia
• Schuylkill
• Somerset
• York

And, the following counties are under a severe thunderstorm watch until 8 p.m.

• Lackawanna
• Luzerne
• Pike
• Susquehanna
• Wayne
• Wyoming

Excessive heat is also expected Thursday, with hot and humid conditions to persist through Saturday, forecasters said. Heat index values could be as high as 108 degrees in parts of Philadelphia metro area counties.

“Dangerous excessive heat expected Thu & Fri,” the National Weather Service Mount Holly station said in a statement. “Avoid strenuous outdoor activity. Drink plenty of water and wear lightweight, loose-fitting, and light-colored clothing. Hot and humid conditions look to last through Sat, but by Sun, it appears we will see some relief.”

So we've got a heat wave coming... how does it stack up to average? It looks like we'll be right around average annual highs Thursday & Friday, so statistically, this has a chance to be the hottest wx of the year. There has certainly been hotter wx in August, so no promises! pic.twitter.com/hqZsbkp8ja
— NWS Mount Holly (@NWS_MountHolly) July 26, 2023

Some of the hottest temperatures of the summer are expected today. 🌡️ Air temps will rise into the mid 80s - mid 90s across central PA this afternoon, with the humidity adding in to make it feel like 95-105°F south of I-80. Stay cool & check on vulnerable neighbors! #PAwx pic.twitter.com/knthuXOtlK
— NWS State College (@NWSStateCollege) July 27, 2023

As of Thursday afternoon, five counties are under an excessive heat warning through Friday night due to expected heat indices up to 110 degrees. The affected counties are:

• Delaware
• Philadelphia
• Chester
• Montgomery
• Bucks

Heat advisories are in effect around the state through Friday evening, with maximum heat indices up to 103 expected in portions of northwest, southeast, and western Pennsylvania.

The following counties are under a heat advisory from 11 a.m. Thursday until 9 p.m. Friday:

• Allegheny
• Armstrong
• Beaver
• Butler
• Clarion
• Fayette
• Greene
• Indiana
• Lawrence
• Mercer
• Venango
• Washington
• Westmoreland

Many central Pennsylvania counties are also under heat advisories, as well.

A heat advisory is in effect from noon Thursday to 8 p.m. Friday for the following counties:

• Franklin
• Perry
• Dauphin
• Lebanon
• Cumberland
• Adams
• York
• Lancaster
• Juniata
• Lycoming
• Union
• Snyder
• Montour
• Northumberland
• Columbia
• Schuylkill
• Centre
• Blair
• Huntingdon
• Mifflin
• Bedford
• Fulton
• Clinton

“Extreme heat and humidity will significantly increase the potential for heat related illnesses, particularly for those working or participating in outdoor activities,” the National Weather Service said. “Drink plenty of fluids, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. Young children and pets should never be left unattended in vehicles under any circumstances.”

Hot and humid conditions will persist through Saturday; Friday is expected to see sunny skies before another possible round of thunderstorms on Saturday afternoon, the weather service said.

Forecasters say that fans of cooler temperatures may get a break from the scorching heat soon as a cold front over the weekend is expected to bring cooler weather by Sunday with temperatures dropping to 85 degrees by Sunday afternoon and around 62 degrees by Sunday night.

Here’s the latest forecast around Pennsylvania, per the National Weather Service:

Thursday: Sunny, with a high near 93. Heat index values as high as 102. Southwest wind 10 to 15 mph.

Thursday Night: A chance of showers and thunderstorms, mainly before 11 p.m. Mostly cloudy, with a low around 75. Southwest wind 5 to 10 mph. Chance of precipitation is 50 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Friday: Patchy fog before 8 a.m. Otherwise, mostly sunny, with a high near 96. Heat index values as high as 107. Southwest wind 5 to 15 mph.

Friday Night: A chance of showers and thunderstorms, mainly before 11 p.m. Some of the storms could produce gusty winds and heavy rain. Partly cloudy, with a low around 76. Southwest wind around 5 mph. Chance of precipitation is 30 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Saturday: A chance of showers and thunderstorms, mainly after 2 p.m. Some of the storms could produce gusty winds and heavy rain. Mostly sunny, with a high near 95. Southwest wind 10 to 15 mph. Chance of precipitation is 30 percent. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

Saturday Night: Showers and thunderstorms likely, mainly between 8 p.m. and 11 p.m. Some of the storms could produce gusty winds and heavy rain. Mostly cloudy, with a low around 70. Chance of precipitation is 60 percent. New rainfall amounts between a half and three quarters of an inch possible.

Sunday: A chance of showers between 8 a.m. and 2 p.m. Mostly sunny, with a high near 85. Chance of precipitation is 30 percent.

Sunday Night: Partly cloudy, with a low around 64.