A severe weather alert has been issued for Saturday, affecting over 25 million people from eastern Pennsylvania to southern Maine. This includes major cities such as Philadelphia, New York City, Allentown, Poughkeepsie, Hartford, Manchester, and Portland.

The National Weather Service warns of damaging winds, large hail, and lightning, particularly in the early evening and overnight hours. There is also a slight chance of brief tornadoes in some areas. Flash flooding is a significant concern, especially from Philadelphia to Bridgeport, Connecticut, where the risk is rated Level 2 on a scale of 4.

Heavy rain is expected due to multiple rounds of storms, which may lead to localized flooding, particularly in areas prone to such conditions. The storms are forecasted to begin after noon on Saturday, continuing into the night.

In Philadelphia and New York City, severe weather is anticipated between 2 p.m. and 8 p.m. Poughkeepsie and Hartford could see storms as early as 2 p.m., lasting until about 6 to 8 p.m. Meanwhile, Portland and Boston are expected to experience heavy rain from 4 p.m. to 10 p.m., with rain persisting overnight.

While Boston is not facing the highest risk for flash flooding or severe weather, strong storms are still expected in the area. Rain showers are likely to linger into Sunday morning as the cold front moves through. Conditions are expected to improve by Sunday afternoon, bringing cooler air to the region.