'Ring Of Fire' Thunderstorms To Break Up Intense Heat In PA

A large swath of thunderstorms surrounding a massive heat dome could bring a "ring of fire" to the mid-Atlantic region Wednesday evening, breaking up the record-breaking heat that has descended upon the region.

The pattern is referred to in the weather community as a "ring of fire" because thunderstorms form along the edges of the heat dome, AccuWeather explained.

The massive heat dome has engulfed much of the country from Texas to New England. Because the heat dome is warm through most layers of the atmosphere, clouds and storms have difficulty forming.

"However, on the edges of the heat, especially along the northern and western flanks thereof, the air is cooler well above the ground, which makes it easier for clouds to tower and produce thunderstorms," AccuWeather said. "Within this ring, there can be spotty, individual thunderstorms, large clusters of thunderstorms or a solid line of storms that can repeat or meander back and forth as hot and cool air change hands."

In the Philadelphia region, storms are expected later in the day Wednesday and could occur into the night.

An extreme heat warning is in place through Wednesday at 8 p.m, when the high temperature is expected to reach 98. Wednesday night will see a temperature dip to the mid-70s, with low temperatures in the mid-60s by Thursday.

It will be noticeably cooler on Friday, when a high temperature of 74 is predicted along with mostly cloudy skies.

This week's heat has broken records, according to the National Weather Service out of Mount Holly.

Seven of the agency's nine climate stations tied or broke record highs on Monday, including in Philadelphia, where it reached 99 degrees. It also reached 99 degrees in Reading and Wilmington, Delaware. Some climate stations reported reaching 100 degrees on Tuesday.

There were low temperature records as well.

Eight of the NWS in Mount Holly's record warmest low temperatures were set or tied on Monday, including in Atlantic City, Philadelphia and Trenton.

Another dangerous hot & humid day is in store with most places expecting head indices of 100° or more. 🌡

When will we see relief? The heat & humidity linger Wed, but noticeably break Thu and especially Fri. Warmer again over the weekend, but temps will be closer to normal. pic.twitter.com/JyNvFrTpgv
— NWS Mount Holly (@NWS_MountHolly) June 24, 2025

Here is the local forecast:

Tuesday: Sunny and hot, with a high near 101. Heat index values as high as 105. Northwest wind around 5 mph.

Tuesday night: Mostly clear, with a low around 81. Northwest wind around 5 mph becoming calm in the evening.

Wednesday: A chance of showers and thunderstorms after 2pm. Sunny and hot, with a high near 98. Heat index values as high as 105. Calm wind becoming northwest around 5 mph in the afternoon. Chance of precipitation is 30%. 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. Partly cloudy, with a low around 77. West wind around 5 mph becoming calm in the evening. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Thursday: A chance of showers before 11 am, then a chance of showers and thunderstorms between 11am and 2pm, then showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 86. East wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

Thursday Night: Showers likely and possibly a thunderstorm before 8 pm, then a chance of showers and thunderstorms between 8pm and 2am, then a chance of showers after 2am. Mostly cloudy, with a low around 65. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

Friday: A chance of showers after 2pm. Mostly cloudy, with a high near 74. Chance of precipitation is 30%.