A cold front triggered several broken lines of severe thunderstorms across south-central and southeastern Pennsylvania during the late morning and early afternoon. A few discrete, organized storms developed over the lower Susquehanna Valley. The convective environment was characterized by strong surface heating of a moist low level air mass which resulted in moderate instability ahead of the approaching cold front. In addition, strong westerly wind flow and shear in the middle and upper atmosphere contributed to support organized storm structures that produced numerous reports of damaging winds and isolated large hail. The majority of the severe weather was confined to the lower Susquehanna Valley between 1300 and 1500 EDT.

Hail in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:49:00 to 25-JUL-10 12:49:00 (EST-5)
Location: HAMILTON PARK
Magnitude: 1.00 
Reported by: Broadcast Media

Thunderstorm Wind in ADAMS, PENNSYLVANIA
From 25-JUL-10 12:52:00 to 25-JUL-10 12:52:00 (EST-5)
Location: ORRTANNA
Magnitude: 62.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: COOP Observer

Orrtanna COOP observer measured a 71 mph thunderstorm wind gust. The severe wind gust knocked down trees and large limbs.

Thunderstorm Wind in SCHUYLKILL, PENNSYLVANIA
From 25-JUL-10 12:45:00 to 25-JUL-10 12:45:00 (EST-5)
Location: FERNDALE
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees near Shenandoah.

Funnel Cloud in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:24:00 to 25-JUL-10 12:24:00 (EST-5)
Location: BAINBRIDGE
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Funnel cloud sighted north of Bainbridge.

Hail in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 12:10:00 to 25-JUL-10 12:10:00 (EST-5)
Location: HUMMELSTOWN
Magnitude: 1.25 
Reported by: Public

Funnel Cloud in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:32:00 to 25-JUL-10 12:32:00 (EST-5)
Location: MARIETTA AFS
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

A funnel cloud was reported in Marietta.

Thunderstorm Wind in CAMBRIA, PENNSYLVANIA
From 25-JUL-10 11:00:00 to 25-JUL-10 11:00:00 (EST-5)
Location: SUMMERHILL
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees across Summerhill Township.

Thunderstorm Wind in CUMBERLAND, PENNSYLVANIA
From 25-JUL-10 12:40:00 to 25-JUL-10 12:40:00 (EST-5)
Location: SHIPPENSBURG
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down trees in Shippensburg.

Thunderstorm Wind in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 12:00:00 to 25-JUL-10 12:00:00 (EST-5)
Location: PAXTONIA
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees at the intersection of Earl Drive and Village Road near Colonial Park.

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:42:00 to 25-JUL-10 12:42:00 (EST-5)
Location: (LNS)LANCASTER ARPT
Magnitude: 53.00 MG
Reported by: ASOS

Lancaster ASOS (KLNS) measured a 53 knot thunderstorm wind gust at 1342 EDT.

Thunderstorm Wind in YORK, PENNSYLVANIA
From 25-JUL-10 13:25:00 to 25-JUL-10 13:25:00 (EST-5)
Location: SEVEN VLYS
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph uprooted three trees 2 miles east of Seven Valleys.

Thunderstorm Wind in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 12:00:00 to 25-JUL-10 12:00:00 (EST-5)
Location: ESTHERTON
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down several 5-inch diameter tree limbs and blew them through a house window. The severe winds also knocked down trees and wires, causing power outages.

Thunderstorm Wind in CAMBRIA, PENNSYLVANIA
From 25-JUL-10 10:55:00 to 25-JUL-10 10:55:00 (EST-5)
Location: VINTONDALE
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: COOP Observer

Thunderstorm winds estimated near 60 mph knocked down trees west of Nanty-Glo.

Thunderstorm Wind in CLINTON, PENNSYLVANIA
From 25-JUL-10 11:40:00 to 25-JUL-10 11:40:00 (EST-5)
Location: LOCK HAVEN
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph knocked down numerous trees and wires in Lock Haven.

Hail in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 12:10:00 to 25-JUL-10 12:10:00 (EST-5)
Location: HUMMELSTOWN
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 12:05:00 to 25-JUL-10 12:05:00 (EST-5)
Location: RUTHERFORD HGTS
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees on North 67th Street and James Way Plaza in Rutherford Heights.

Thunderstorm Wind in LEBANON, PENNSYLVANIA
From 25-JUL-10 12:20:00 to 25-JUL-10 12:20:00 (EST-5)
Location: CAMPBELLTOWN
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees and wires in South Londonderry Township.

Hail in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:32:00 to 25-JUL-10 12:32:00 (EST-5)
Location: MANHEIM
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:49:00 to 25-JUL-10 12:49:00 (EST-5)
Location: HAMILTON PARK
Magnitude: 61.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm winds near 70 mph were measured at WGAL. The severe winds knocked down numerous trees in the Lancaster area.

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:50:00 to 25-JUL-10 12:50:00 (EST-5)
Location: WEST LANCASTER
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires on Clover Hill Road in Manor Township. A 53-year-old woman was found dead in her yard on the 2100 block of Clover Hill Road around 1300 EDT. Police suspect that the women left her residence to investigate the storm damage, and was electrocuted by a downed wire.

Thunderstorm Wind in COLUMBIA, PENNSYLVANIA
From 25-JUL-10 12:35:00 to 25-JUL-10 12:35:00 (EST-5)
Location: FERNVILLE
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph tore a section of the roof off the arts building at the Bloomsburg Fairgrounds.

Thunderstorm Wind in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 12:10:00 to 25-JUL-10 12:10:00 (EST-5)
Location: ROYALTON
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees on the 400 block of Cathrine Street in Middletown Borough.

Hail in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 12:15:00 to 25-JUL-10 12:15:00 (EST-5)
Location: HERSHEY
Magnitude: 1.00 
Reported by: Public

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 25-JUL-10 12:38:00 to 25-JUL-10 12:43:00 (EST-5)
Location: LITITZ
Magnitude: 70.00 EG
Property damage: 20.00K
Crop damage: 0.00K
Reported by: NWS Storm Survey

NWS meteorologists and Lancaster County Emergency Management officials surveyed thunderstorm wind damage in Lititz, PA. Severe thunderstorm winds knocked down 50 to 75 trees onto many homes and vehicles. The highest wind gusts were estimated between 70 and 80 mph. Storm damage affected nearly the entire area in the vicinity of Lititz and Warwick Township. It was determined that the cause of the damage was straight-line downburst winds. No injuries were reported.

Thunderstorm Wind in FRANKLIN, PENNSYLVANIA
From 25-JUL-10 12:20:00 to 25-JUL-10 12:20:00 (EST-5)
Location: ROXBURY
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees on Timmons Mountain just east of Willow Hill.

Thunderstorm Wind in DAUPHIN, PENNSYLVANIA
From 25-JUL-10 11:58:00 to 25-JUL-10 11:58:00 (EST-5)
Location: WEST END
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down tress along Emerald Street in Harrisburg. The trees blocked street access for a brief time.

Thunderstorm Wind in ADAMS, PENNSYLVANIA
From 25-JUL-10 12:55:00 to 25-JUL-10 12:55:00 (EST-5)
Location: GARDNERS
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down trees and wires in Gardners.

Thunderstorm Wind in FRANKLIN, PENNSYLVANIA
From 25-JUL-10 12:19:00 to 25-JUL-10 12:19:00 (EST-5)
Location: WILLOW HILL
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees along SR 641 (Timmons Road) just east of Willow Hill.

Thunderstorm Wind in YORK, PENNSYLVANIA
From 25-JUL-10 13:20:00 to 25-JUL-10 13:20:00 (EST-5)
Location: YORK
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down trees and large limbs in York.