Philadelphia is in the grip of a sweltering heatwave this week, with “feels-like” temperatures soaring close to the triple-digit mark on Wednesday and even hotter conditions expected on Thursday, accompanied by the threat of severe thunderstorms.

A Heat Advisory is currently in effect for Philadelphia and surrounding counties until 8 PM EDT on Thursday, as the combination of high humidity and actual air temperatures pushes the heat index to dangerous levels. Forecasters warn that the “feels-like” temperature could reach as high as 99 degrees Fahrenheit on both Wednesday and Thursday.

Wednesday saw humid conditions persist, making the actual high-80s temperature feel significantly hotter. While scattered pop-up storms were possible, the main weather concern for the day remained the oppressive heat.

However, Thursday is marked as a “NEXT Weather Alert” day, as a more potent line of storms is anticipated to sweep through the Delaware Valley in the afternoon and early evening, roughly between 5 PM and 9 PM. These storms carry the potential for severe weather, including lightning, heavy rain, strong wind gusts, and even the possibility of isolated tornadoes. The risk for severe weather on Thursday has been elevated to a Level 2 out of 5, indicating a higher chance of impactful conditions.

Residents are urged to take precautions against the extreme heat. This includes staying well-hydrated, seeking refuge in air-conditioned environments, limiting strenuous outdoor activities, especially during peak heat hours, and checking on vulnerable individuals such such as the elderly and pets.

Looking ahead, Friday, the official start of summer, is expected to bring a brief reprieve with sunnier skies. However, the heatwave is forecast to continue into the weekend and potentially next week, with temperatures once again climbing into the 90s, possibly even touching 100 degrees by early next week. Authorities are closely monitoring the situation and advise the public to stay informed about the latest weather updates.