The strong pressure gradient (difference) between an intensifying strong low pressure system and a high pressure system in the Ohio Valley caused strong northwest winds to occur across Pennsylvania from the evening of the 12th following a cold frontal passage through the daytime hours on the 13th. Peak wind gusts averaged around  50 mph and the highest winds occurred overnight on the 12th. The prolonged period of strong winds caused weak tree limbs, trees and power lines to be knocked down and caused widely scattered power outages. Downed trees and/or power lines blocked roadways in Delaware (Concordville and Lansdowne), Chester (Willistown), Montgomery (Ambler), Lehigh (Allentown) and Philadelphia Counties.
Peak wind gusts included 56 mph in Newtown (Delaware County), 54 mph in Port Richmond (Philadelphia), 53 mph in Mount Pocono (Monroe County), Coatesville (Chester County) and the Northeast Philadelphia Airport, 49 mph in Reading and Lenhartsville (Berks County) and Strickersville and Kelton (Chester County), 48 mph at the Lehigh Valley and Philadelphia International Airports, 45 mph in Perkasie and Doylestown (Bucks County) and 44 mph in Pottstown (Montgomery County).
The low pressure system responsible for the strong winds emerged from the Rockies on the evening of the 10th. It reached central Missouri on the evening of the 11th and western Pennsylvania on the afternoon of the 12th. It already was an intense 984 millibar low pressure system. The northeast moving 982 millibar low pressure system reached central New Jersey at 8 p.m. EDT on the 12th as its cold front just about cleared the Eastern Shore. The 981 millibar low pressure system was near Boston, Massachusetts at 11 p.m. EDT on the 12th and reached Nova Scotia as a 976 millibar low pressure system at 5 a.m. EDT on the 13th. It continued to move northeast through the Canadian Maritimes during the day on the 13th and very slowly weakened. By evening on the 13th, the high pressure system was close enough to the Eastern Shore that the pressure gradient (difference) weakened and the strong winds stopped.

Strong Wind in BERKS, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 43.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in CARBON, PENNSYLVANIA
From 12-MAR-14 19:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in MONROE, PENNSYLVANIA
From 12-MAR-14 19:30:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 46.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: ASOS

Strong Wind in LEHIGH, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 42.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: ASOS

Strong Wind in NORTHAMPTON, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 42.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: ASOS

Strong Wind in WESTERN CHESTER, PENNSYLVANIA
From 12-MAR-14 19:30:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 46.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: AWOS

Strong Wind in EASTERN CHESTER, PENNSYLVANIA
From 12-MAR-14 19:30:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 43.00 MG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in WESTERN MONTGOMERY, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in EASTERN MONTGOMERY, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in UPPER BUCKS, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in LOWER BUCKS, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 40.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in DELAWARE, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 49.00 MG
Property damage: 8.00K
Crop damage: 0.00K
Reported by: Mesonet

Strong Wind in PHILADELPHIA, PENNSYLVANIA
From 12-MAR-14 20:00:00 to 13-MAR-14 14:00:00 (EST-5)
Magnitude: 47.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Mesonet