The volatility of the atmosphere has shifted east as the Storm Prediction Center has placed northwest Pennsylvania and most of central New York under a moderate risk for severe weather. A "Slight Risk" encompasses the most of Pennsylvania and all of Maryland, New Jersey and Delaware, which includes this area. This is all ahead of strong cold front currently working through Ohio and Western PA. This cold front will wipe away the 90-degree heat and reduce the humidity for a majority of the rest of the work week, but we have some thunderstorms to get through.
Temperatures in the lower to mid-90's ahead of this cold front act as a primer for the explosive nature of these storms. Looking into the evening, the Storm Prediction Center is anticipating issuing a Severe Thunderstorm Watch for the Philadelphia metro, however, as of this posting, there was not one issued. There is still an Excessive Heat Warning until 7pm tonight and a Flash Flood Watch into tonight. These storms tonight may feature heavy, torrential rains, frequent lightning, high winds and small hail. It'll still be warm and muggy overnight with lows in the mid-60's to lower-70's. The showers and thunderstorms may stick around into tomorrow morning, with a chance of showers and an isolated storm possible by mid-morning. Then, skies will clear, and it will be noticeably less humid by tomorrow afternoon and evening. Temperatures tomorrow in the mid-80's close to the city, upper 80's to the south and lower 80's north and west.
The rest of the week looks much cooler than the past few days, and quieter. Thursday will be sunny and cooler, a great day to open the windows and air out the house. Temperatures in the lower 80's. Friday features more sun, but by the late afternoon, clouds start rolling in with scattered showers. Overnight Friday into Saturday, showers start to become more steady. Saturday will be mostly overcast with off and on showers. Sunday is looking like the best day of the weekend, with cool temperatures and partly cloudy skies. Monday will be mostly sunny and warmer and Tuesday will be unsettled, with a chance of showers and temperatures hovering around 80-degrees.
So it looks like the biggest hurdle to get over is tonight. Make sure your NOAA Weather Radios have fresh batteries as well as your flashlights.