Leaf blower

Thunderstorm gusts ripped through the region during the early morning hours, and the atmosphere got a second wind this afternoon.

Gusts of 41 m.p.h. were reported at the official automated station at Philadelphia International Airport at 2 and 3 p.m., and 40, at 4 p.m.

A wind advisory remains in effect until 8 p.m., but the National Weather Service expects the gusts to calm down after dark. The gust reading was down to 37 at 5 p.m.

The winds rushed in behind a cool front that crossed the region this morning, its arrival announced by considerable fanfare. 

The thunderstorm damage occurred between 3 a.m. and 5 a.m., with over 30,000 power outages reported, as mentioned in Peter Mucha's online story.A 54 m.p.h. gust was measured in Trenton, with roofs ripped off the Trenton airport buildings and some planes flipped over, according to a weather service report.

This is the time of year when winds pick up around here after a summer lull. Based on weather-service data, on average wind speeds jump 17 percent from August through November -- from 8 m.p.h. to 9.4.

The average winds reach a peak in March, at 10.9 m.p.h., and then begin the slow descent to August. But the real difference between a March and November wind is a few billion leaves.

Incidentally, we once attempted to calculate the number of leaves on the region's trees. We were informed that we were crazy, but using data from the U.S. Forest Service, we came up with a rough estimate of five billion leaves on six million trees in Philadelphia and its four Pennsylvania neighbors.

We will not stand by the precision, but you probably get the idea. On a day with winds like this, five billion may seem conservative.

The August average speed is  

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