A very strong cold frontal passage produced strong to high winds across Eastern Pennsylvania during the afternoon and early evening on the 25th. Peak wind gusts averaged 50 to 60 mph, highest around the local Philadelphia area. The winds downed trees, tree limbs and power lines. The high wind gusts occurred during the first hour after the cold front passed while lesser, but still strong, wind gusts persisted into the first half of the evening.  In Delaware County, the high winds tore two roofs off of homes on Green Street in Marcus Hook. A third home was damaged by the flying debris. In Chester County, in Tredyffrin Township, a downed tree crashed into the bedroom of a Mancill Road home. No injuries were reported in either county. At Philadelphia International Airport, flight delays averaged 90 minutes and about 100 flights were cancelled. PECO Energy reported about 45,000 of its customers lost power in southeastern Pennsylvania.
Peak wind gusts included 63 mph at the Philadelphia International Airport, 59 mph at the Northeast Philadelphia Airport, 56 mph in London Grove (Chester County), 55 mph in Drexel Hill (Delaware County), 54 mph at the Lehigh Valley International Airport, 53 mph in Newbold (Bucks County) and Coatesville (Chester County), 52 mph in Doylestown (Bucks County) and 51 mph at Mount Pocono (Monroe County).
The strong to high winds were caused by the pressure difference between a large high pressure system in the middle of the United States and an intense low pressure system that moved through eastern New England and the Canadian Maritimes. The winds received an additional boost from the large atmospheric pressure rises that occurred just after the cold front passed.

Strong Wind in NORTHAMPTON, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 21:00:00 (EST-5)
Magnitude: 47.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in PHILADELPHIA, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 17:00:00 (EST-5)
Magnitude: 55.00 MG
Property damage: 25.00K
Crop damage: 0.00K
Reported by: ASOS

Strong Wind in MONROE, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 21:00:00 (EST-5)
Magnitude: 44.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: ASOS

Strong Wind in BERKS, PENNSYLVANIA
From 25-FEB-11 14:00:00 to 25-FEB-11 20:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in MONTGOMERY, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 21:00:00 (EST-5)
Magnitude: 43.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in CARBON, PENNSYLVANIA
From 25-FEB-11 14:00:00 to 25-FEB-11 20:00:00 (EST-5)
Magnitude: 43.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in BUCKS, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 21:00:00 (EST-5)
Magnitude: 46.00 MG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: C-MAN Station

Strong Wind in LEHIGH, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 21:00:00 (EST-5)
Magnitude: 47.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: ASOS

High Wind in CHESTER, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 17:00:00 (EST-5)
Magnitude: 52.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Newspaper

High Wind in DELAWARE, PENNSYLVANIA
From 25-FEB-11 15:00:00 to 25-FEB-11 17:00:00 (EST-5)
Magnitude: 55.00 MG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: ASOS