Low pressure tracked east-northeast from the Lower Great Lakes region into the Northeast states, while a cold front trailed southwestward from the surface low through the Ohio Valley and Southern Plains states. Hot and humid conditions ahead of the cold front allowed for strong instability, which allowed for vigorous thunderstorm development by the mid-afternoon. A belt of strong winds aloft on the southern edge of a potent mid-upper level trough over the Upper Great Lakes extended from the Ohio Valley into Pennsylvania. These winds helped to organize storms into lines and bowing segments. In addition, a tornado threat existed over northern Pennsylvania in an area of strong low-level shear in the vicinity of a retreating, diffuse warm front.
Widespread damaging winds accompanied an intense line of severe thunderstorms that moved from the northwest mountains into the lower Susquehanna Valley from the mid-afternoon into the late evening hours. An EF0 tornado was confirmed near Coudersport at 1515 EDT. Two areas of concentrated straight-line wind damage were also surveyed in McKean and Potter Counties, with estimated maximum winds between 70 and 90 mph. A 66-year-old woman was killed by a falling tree near Genesee in northern Potter County.

Hail in COLUMBIA, PENNSYLVANIA
From 26-JUL-12 16:15:00 to 26-JUL-12 16:15:00 (EST-5)
Location: BERWICK
Magnitude: 1.00 
Reported by: Trained Spotter

Thunderstorm Wind in CLEARFIELD, PENNSYLVANIA
From 26-JUL-12 15:10:00 to 26-JUL-12 15:10:00 (EST-5)
Location: GRAMPIAN
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Storm Chaser

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

Thunderstorm Wind in MCKEAN, PENNSYLVANIA
From 26-JUL-12 13:40:00 to 26-JUL-12 13:50:00 (EST-5)
Location: LEWIS RUN
Magnitude: 78.00 EG
Property damage: 15.00K
Reported by: NWS Storm Survey

An official NWS storm survey found widespread straight-line wind damage near Lewis Run. A broad swath of wind damage (approximately 10 miles wide) brought down dozens of trees in the area. Within the relatively wide swath of downed trees, an embedded microburst was confirmed along US 219. The microburst was approximately 200 yards long with estimated maximum winds between 70 and 90 mph. Five houses and two outbuildings sustained moderate structural damage due to fallen trees.

Thunderstorm Wind in COLUMBIA, PENNSYLVANIA
From 26-JUL-12 16:15:00 to 26-JUL-12 16:15:00 (EST-5)
Location: BERWICK
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

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

Thunderstorm Wind in YORK, PENNSYLVANIA
From 26-JUL-12 19:00:00 to 26-JUL-12 19:00:00 (EST-5)
Location: GLEN ROCK
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Glen Rock.

Thunderstorm Wind in SOMERSET, PENNSYLVANIA
From 26-JUL-12 17:10:00 to 26-JUL-12 17:10:00 (EST-5)
Location: WINDBER
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down numerous trees in and around Windber.

Thunderstorm Wind in CAMBRIA, PENNSYLVANIA
From 26-JUL-12 16:16:00 to 26-JUL-12 16:16:00 (EST-5)
Location: EBENSBURG
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down numerous trees in Ebensburg.

Thunderstorm Wind in POTTER, PENNSYLVANIA
From 26-JUL-12 14:10:00 to 26-JUL-12 14:15:00 (EST-5)
Location: KINNEY
Magnitude: 78.00 EG
Property damage: 10.00K
Reported by: NWS Storm Survey

An official NWS storm survey found widespread straight-line wind damage near Genesee. The survey team identified two areas of more concentrated wind damage which were classified as embedded microbursts. The overall area of wind damage covered an area approximately 1 mile wide and 3 miles Long from Kinney Road eastward through Hickox to Grover Hollow Road. The first area of concentrated damage, consisting of dozens of downed trees, occurred along Kinney Road about 1 mile east of the intersection with Corcoran road. The second concentrated area of microburst damage occurred along Hickox and Grover Hollow Roads. At this location, seven homes sustained minor structural damage. The maximum estimated wind speeds associated with the microburst damage was 90 mph.
An 66-year-old Andover, NY, woman was killed while trying to evacuate her family from a campsite located along Wintergreen Road in Hickox. Officials said the woman was fastening her Great Grand-daughter into a safety-seat in her vehicle after receiving a text message alerting her of a tornado warning. The woman and her two Grandchildren, ages 19 and 20, were planning on evacuating the campsite, but she was struck by a falling tree in the process. Authorities said the tree struck the Grandmother in the head, killing her instantly. She was pronounced dead at the scene by Potter County Coroner. Witnesses said the tree was struck by lightning before falling. One of her Grand-daughters was also struck and injured by the falling tree while attempting to help her Grandmother. She survived but suffered injuries to her leg and arm and was transported to the hospital.

Thunderstorm Wind in BEDFORD, PENNSYLVANIA
From 26-JUL-12 17:10:00 to 26-JUL-12 17:10:00 (EST-5)
Location: WOODBURY
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down numerous trees in and around Woodbury.

Thunderstorm Wind in DAUPHIN, PENNSYLVANIA
From 26-JUL-12 17:00:00 to 26-JUL-12 17:00:00 (EST-5)
Location: LYKENS
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down numerous trees in and around Lykens.

Thunderstorm Wind in CAMBRIA, PENNSYLVANIA
From 26-JUL-12 16:37:00 to 26-JUL-12 16:37:00 (EST-5)
Location: BROWNSTOWN
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph knocked down large tree limbs in Westmont.

Thunderstorm Wind in WARREN, PENNSYLVANIA
From 26-JUL-12 13:00:00 to 26-JUL-12 13:00:00 (EST-5)
Location: SUGAR GROVE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Sugar Grove.

Thunderstorm Wind in MCKEAN, PENNSYLVANIA
From 26-JUL-12 13:56:00 to 26-JUL-12 13:56:00 (EST-5)
Location: SMETHPORT
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

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

Thunderstorm Wind in CLINTON, PENNSYLVANIA
From 26-JUL-12 15:20:00 to 26-JUL-12 15:20:00 (EST-5)
Location: LOCKPORT
Magnitude: 56.00 MG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 65 mph knocked down trees in and around Lock Haven.

Thunderstorm Wind in LEBANON, PENNSYLVANIA
From 26-JUL-12 17:20:00 to 26-JUL-12 17:20:00 (EST-5)
Location: FREDERICKSBURG
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees northwest of Fredericksburg.

Thunderstorm Wind in BLAIR, PENNSYLVANIA
From 26-JUL-12 16:15:00 to 26-JUL-12 16:15:00 (EST-5)
Location: HOLIDAYSBURG
Magnitude: 50.00 EG
Reported by: Newspaper

Thunderstorm winds estimated near 60 mph knocked down trees in Hollidaysburg. One tree fell on a house, but the extent of damage was unknown.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 26-JUL-12 15:26:00 to 26-JUL-12 15:26:00 (EST-5)
Location: MARSH HILL
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down trees along SR 14 north of Trout Run.

Thunderstorm Wind in SOMERSET, PENNSYLVANIA
From 26-JUL-12 16:50:00 to 26-JUL-12 16:50:00 (EST-5)
Location: TRUST
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires along SR 271 (Menoher Hwy) in extreme northwest Somerset County. The downed wires closed the road.

Thunderstorm Wind in LEBANON, PENNSYLVANIA
From 26-JUL-12 17:25:00 to 26-JUL-12 17:25:00 (EST-5)
Location: FREDERICKSBURG
Magnitude: 70.00 EG
Property damage: 10.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 80 mph removed a portion of a gas station roof and caused a partial collapse of a cinder-block wall. The enhanced straight-line wind damage was likely the result of a microburst. Eye-witness reports indicate some swirling with the wind, and some damage being picked up and lifted in a rotating pattern near the edge of the microburst. It is therefore concluded that a brief gustnado spin up occurred in association with the microburst.

Thunderstorm Wind in POTTER, PENNSYLVANIA
From 26-JUL-12 14:08:00 to 26-JUL-12 14:08:00 (EST-5)
Location: ROULETTE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down large trees in Roulette.

Thunderstorm Wind in POTTER, PENNSYLVANIA
From 26-JUL-12 14:30:00 to 26-JUL-12 14:30:00 (EST-5)
Location: AUSTIN
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: COOP Observer

Thunderstorm winds estimated near 60 mph knocked down trees along SR 872 near Austin.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 26-JUL-12 15:25:00 to 26-JUL-12 15:25:00 (EST-5)
Location: JERSEY SHR
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down trees in Jersey Shore.

Thunderstorm Wind in CAMBRIA, PENNSYLVANIA
From 26-JUL-12 15:40:00 to 26-JUL-12 15:40:00 (EST-5)
Location: GLASGOW
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

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

Thunderstorm Wind in SOMERSET, PENNSYLVANIA
From 26-JUL-12 17:20:00 to 26-JUL-12 17:20:00 (EST-5)
Location: BARRONVALE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down several trees in Seven Springs.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 26-JUL-12 15:35:00 to 26-JUL-12 15:35:00 (EST-5)
Location: LINDEN
Magnitude: 50.00 EG
Property damage: 2.50K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph knocked down large tree limbs near Linden just west of Williamsport.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 26-JUL-12 15:55:00 to 26-JUL-12 15:55:00 (EST-5)
Location: CLARKSTOWN
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph ripped a door from a residential home on Main Street in Muncy. SR 442 was closed from downed trees and utility wires just east of Muncy between Fogelman and Clarkstown Roads.

Thunderstorm Wind in SOMERSET, PENNSYLVANIA
From 26-JUL-12 17:27:00 to 26-JUL-12 17:27:00 (EST-5)
Location: CONFLUENCE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

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

Thunderstorm Wind in ELK, PENNSYLVANIA
From 26-JUL-12 14:15:00 to 26-JUL-12 14:15:00 (EST-5)
Location: RIDGWAY
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down numerous trees and utility wires around Ridgway.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 26-JUL-12 15:43:00 to 26-JUL-12 15:43:00 (EST-5)
Location: NEWBERRY
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph blew a roof from a building at Penn College.

Thunderstorm Wind in SULLIVAN, PENNSYLVANIA
From 26-JUL-12 15:45:00 to 26-JUL-12 15:45:00 (EST-5)
Location: MILLVIEW
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees along SR3009 and 154 near Worlds End State Park. Firefighters had to rescue a man who was injured and trapped when a tree fell onto his tent. The man was rescued and transported to a nearby hospital. His injuries were not life-threatening.

Thunderstorm Wind in ELK, PENNSYLVANIA
From 26-JUL-12 14:20:00 to 26-JUL-12 14:20:00 (EST-5)
Location: JOHNSONBURG
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down numerous trees and utility wires around Johnsonburg.

Thunderstorm Wind in CAMBRIA, PENNSYLVANIA
From 26-JUL-12 15:48:00 to 26-JUL-12 15:48:00 (EST-5)
Location: BARNESBORO
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down trees in Northern Cambria.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 26-JUL-12 15:45:00 to 26-JUL-12 15:45:00 (EST-5)
Location: (IPT)WILLIAMSPORT AR
Magnitude: 51.00 MG
Reported by: ASOS

The ASOS at the Williamsport Regional Airport (KIPT) recorded a peak thunderstorm wind gusts of 59 mph.

Thunderstorm Wind in BEDFORD, PENNSYLVANIA
From 26-JUL-12 17:15:00 to 26-JUL-12 17:15:00 (EST-5)
Location: NEW PARIS
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down trees in New Paris.

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 26-JUL-12 17:49:00 to 26-JUL-12 17:49:00 (EST-5)
Location: DURLACH
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees in West Cocalico and Clay Townships.

Thunderstorm Wind in ELK, PENNSYLVANIA
From 26-JUL-12 14:25:00 to 26-JUL-12 14:25:00 (EST-5)
Location: KAULMONT
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down numerous trees and utility wires around St. Mary's.

Thunderstorm Wind in CAMERON, PENNSYLVANIA
From 26-JUL-12 14:37:00 to 26-JUL-12 14:37:00 (EST-5)
Location: EMPORIUM
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph knocked down several large trees in Emporium.

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 26-JUL-12 17:48:00 to 26-JUL-12 17:48:00 (EST-5)
Location: BAINBRIDGE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down trees in Conoy Township near Bainbridge.

Thunderstorm Wind in YORK, PENNSYLVANIA
From 26-JUL-12 17:29:00 to 26-JUL-12 17:29:00 (EST-5)
Location: NEW MARKET
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Fairview Township.

Thunderstorm Wind in TIOGA, PENNSYLVANIA
From 26-JUL-12 14:50:00 to 26-JUL-12 14:50:00 (EST-5)
Location: LAWRENCEVILLE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: COOP Observer

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

Thunderstorm Wind in POTTER, PENNSYLVANIA
From 26-JUL-12 14:30:00 to 26-JUL-12 14:30:00 (EST-5)
Location: HARRISON VLY
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph knocked down trees in Harrison Valley.

Thunderstorm Wind in UNION, PENNSYLVANIA
From 26-JUL-12 15:43:00 to 26-JUL-12 15:43:00 (EST-5)
Location: WHITE DEER
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: COOP Observer

Thunderstorm winds estimated near 60 mph knocked down trees in the Allenwood area.

Thunderstorm Wind in CENTRE, PENNSYLVANIA
From 26-JUL-12 15:55:00 to 26-JUL-12 15:55:00 (EST-5)
Location: GATESBURG
Magnitude: 50.00 EG
Property damage: 2.50K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorm winds estimated near 60 mph knocked down large tree limbs and several small trees near Gatesburg.

Thunderstorm Wind in MIFFLIN, PENNSYLVANIA
From 26-JUL-12 16:15:00 to 26-JUL-12 16:15:00 (EST-5)
Location: BURNHAM
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down several large tree branches at the Derry Township Community Park in south Burnham along Derry Park Road and Logan Boulevard. A 16-year-old female was killed when a falling tree branch struck her in the head.

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 26-JUL-12 17:50:00 to 26-JUL-12 17:50:00 (EST-5)
Location: CLAY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: State Official

Delete.

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 26-JUL-12 18:30:00 to 26-JUL-12 18:30:00 (EST-5)
Location: STRASBURG
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Strasburg Township.

Thunderstorm Wind in TIOGA, PENNSYLVANIA
From 26-JUL-12 14:55:00 to 26-JUL-12 14:55:00 (EST-5)
Location: TIOGA
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked down several trees around Tioga Lake.

Thunderstorm Wind in TIOGA, PENNSYLVANIA
From 26-JUL-12 15:00:00 to 26-JUL-12 15:00:00 (EST-5)
Location: ANTRIM
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Public

Thunderstorm winds estimated near 60 mph knocked a few large trees down near Morris.

Thunderstorm Wind in CENTRE, PENNSYLVANIA
From 26-JUL-12 15:55:00 to 26-JUL-12 15:55:00 (EST-5)
Location: OAK HALL
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down a few large trees in the State College area. A large tree fell on a house on Orlando Avenue causing significant structural damage. Another tree fell on a vehicle traveling on Linden Hall Road, with three people sustaining minor injuries.

Thunderstorm Wind in LANCASTER, PENNSYLVANIA
From 26-JUL-12 18:15:00 to 26-JUL-12 18:15:00 (EST-5)
Location: MILLERSVILLE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Thunderstorm winds estimated near 60 mph knocked down large tree limbs in Millersville.

Thunderstorm Wind in YORK, PENNSYLVANIA
From 26-JUL-12 18:15:00 to 26-JUL-12 18:15:00 (EST-5)
Location: YORKSHIRE
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: State Official

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Springettsbury Township.

Thunderstorm Wind in CENTRE, PENNSYLVANIA
From 26-JUL-12 16:02:00 to 26-JUL-12 16:02:00 (EST-5)
Location: PLEASANT GAP
Magnitude: 50.00 EG
Property damage: 5.00K
Reported by: NWS Employee

Thunderstorm winds estimated near 60 mph knocked down trees along Greens Valley Road near Pleasant Gap.

Tornado in POTTER, PENNSYLVANIA
From 26-JUL-12 14:15:00 to 26-JUL-12 14:16:00 (EST-5)
Location: COUDERSPORT
Tornado F-scale: EF0
Property damage: 0.00K
Reported by: NWS Storm Survey

An official NWS storm survey confirmed an EF0 tornado near Coudersport around 1515 EDT. The weak EF0 tornado briefly touched down just northeast of Coudersport and was embedded within a larger swath of straight-line wind damage associated with a bowing line of severe thunderstorms. The convergent damage swath was on a hillside in a heavily wooded area just off of Reese Hollow Road. The short, narrow path of the EF0 tornado was approximately 150 yards wide and less than a quarter mile long. Damage was confined to the forested area with dozens of downed trees, but no damage to houses or structures.