Your summer weather report

[jinx]

I had heard 70mph winds, but they might have hit 90. Whook.

In all, about 350,000 customers lost power as a result of that line of thunderstorms that flashed through the region at lightning speed on Thursday, ripping apart trees from Glenmoore, Chester County, to Hammonton, N.J., and generating winds rarely experienced around here. Gusts reached 75 m.p.h. in Philadelphia, 60, in Camden County, and perhaps 90 in Chester County.

Some of the winds might have hit 90 m.p.h. in Chester County, where Glenmoore was particularly hard hit, said Gigi. "That's just as strong as the winds get around here."
The 215,000 service interruptions in the PECO territory made this one of the biggest outage events ever - No. 11 on the all-time list. About 130,000 Public Service Gas & Electric customers lost power.

Why were the winds so ferocious?
The amazing rapidity of the storms' movement - 55 m.p.h. - certainly was a factor, as was the heat, since storms are fueled by warm air from the surface rising over cooler air. But just as the heat reached a peak in the afternoon and the official thermometer at Philadelphia International Airport hit 97, the highest reading since June 10, 2008, drier air moved in at mid-levels of the atmosphere, said Tony Gigi, a storm specialist at the National Weather Service office in Mount Holly.
As the downdraft rain fell into the drier air, some of it evaporated. When water evaporates, it gives off a cooling effect; that's basically how sweating cools the body. In this case, the massive amount of evaporation gave an extra kick to the downdraft winds, which billowed the tarp at Citizens Bank Park, where the Phillies were hosting Cleveland.
The Philadelphia temperature plummeted 26 degrees within an hour right before the rains arrived, and the airport measured a 75 m.p.h. gust.