The storm picked up steam around 4:30 a.m. as it moved through Montgomery, Bucks, Chester and Philadelphia Counties over the next hour before striking into South Jersey, causing flash flooding in some areas before quickly moving through. Three high tension lines were reported down, causing a fire in Pottstown, Chester County. Firefighters were hampered because of the live power.
Trees were down in Upper Darby, Upper Providence, Eagleville and New Gretna, large limbs in Coatesville and Elverson, according to the National Weather Service.
PECO was reporting outages for 30,000 customers in Southeastern Pennsylvania, about two-thirds of them in Chester County. Atlantic City Electric's tally of South Jersey customers in the dark grew to almost 10,000 by 8 a.m.
Most of the unexpectedly strong storms were heading off the New Jersey and Delaware coasts by 6 a.m., though rain still lingered in Center City and South Jersey.
The storms also caused commuter problems. Service on SEPTA's Paoli/Thorndale line was disrupted for a while, but service was later resumed. The Fox Chase line was disrupted at Lawndale Station because of a downed tree, according to a SEPTA spokeswoman. And Philadelphia Police issued a traffic advisory at 6:45 a.m. saying only one lane of northbound Roosevelt Blvd. at Vankirk St. was getting by because of a downed tree.
One-inch hail was reported in West Chester, and three-quarter-inch or larger pieces in Pottstown, Dublin, Clementon, Woodstown and Boyertown, according to the weather service.
The forecast for the rest of the day calls for possible morning showers then sunny and hot conditions with a high near 100 and heat index values as high as 104. Tonight will see a low of about 75.
Saturday should be mostly sunny with a high of 97, with a chance of thunderstorms at night and a low of 74. Sunday is forecast to be partly sunny with a high near 96. Highs in the 90s are forecast to continue through Thursday.
For more on the forecast, see Philly.com's weather page.