A large subtropical ridge over the western Atlantic and adjacent southeastern United States pumped unseasonably warm air and rich moisture into the Ohio Valley and Mid-Atlantic. This ring-of-fire pattern of moderate instability and strong deep layer wind shear on the northern periphery of the upper-level ridge was conducive for the development of several early-season thunderstorm complexes (QLCS/MCS). The severe storms with embedded bow echoes moved eastward from the Ohio Valley along and south of a strong low-level frontal zone and produced damaging winds and marginally severe hail in central Pennsylvania during the afternoon and evening hours.

Thunderstorm Wind in SOMERSET, PENNSYLVANIA
From 10-APR-13 21:25:00 to 10-APR-13 21:25:00 (EST-5)
Location: ADDISON
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

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

Thunderstorm Wind in CENTRE, PENNSYLVANIA
From 10-APR-13 18:50:00 to 10-APR-13 18:50:00 (EST-5)
Location: (UNV)UNIV PARK STATE
Magnitude: 56.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Official NWS Observations

Thunderstorm winds gusted over 60 mph for several minutes at the NWS office. The peak gust was measured at 64 mph.

Thunderstorm Wind in ELK, PENNSYLVANIA
From 10-APR-13 13:45:00 to 10-APR-13 13:45:00 (EST-5)
Location: KERSEY
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds estimated near 60 mph knocked down trees and utility wires in Fox Township southwest of St. Mary's.

Thunderstorm Wind in ELK, PENNSYLVANIA
From 10-APR-13 13:50:00 to 10-APR-13 13:50:00 (EST-5)
Location: KAULMONT
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds estimated near 60 mph knocked down trees in St. Mary's.

Thunderstorm Wind in CLINTON, PENNSYLVANIA
From 10-APR-13 14:25:00 to 10-APR-13 14:25:00 (EST-5)
Location: TAMARACK
Magnitude: 50.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds estimated near 60 mph knocked down trees in Leidy Township near Tamarack.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 10-APR-13 15:19:00 to 10-APR-13 15:19:00 (EST-5)
Location: (IPT)WILLIAMSPORT AR
Magnitude: 50.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

IPT ASOS measured a peak thunderstorm wind gust of 58 mph at 20:19 UTC.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 10-APR-13 15:25:00 to 10-APR-13 15:25:00 (EST-5)
Location: MONTOURSVILLE
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 just north of Montoursville.

Thunderstorm Wind in MCKEAN, PENNSYLVANIA
From 10-APR-13 17:07:00 to 10-APR-13 17:07:00 (EST-5)
Location: EAST SMETHPORT
Magnitude: 52.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds estimated between 60-70 mph knocked down power poles and utility wires along SR 46 near Smethport.

Thunderstorm Wind in CLEARFIELD, PENNSYLVANIA
From 10-APR-13 18:27:00 to 10-APR-13 18:27:00 (EST-5)
Location: WEST MOSHANNON
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Thunderstorm winds estimated between 60-70 mph knocked down numerous trees in Houtzdale.

Thunderstorm Wind in MIFFLIN, PENNSYLVANIA
From 10-APR-13 19:15:00 to 10-APR-13 19:15:00 (EST-5)
Location: SIGLERVILLE
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds estimated between 60-70 mph knocked down trees in Armagh Township.

Hail in MIFFLIN, PENNSYLVANIA
From 10-APR-13 16:15:00 to 10-APR-13 16:15:00 (EST-5)
Location: BURNHAM
Magnitude: 1.00 
Reported by: Emergency Manager

Quarter-size hail (1 inch) reported in Burnham.

Thunderstorm Wind in ELK, PENNSYLVANIA
From 10-APR-13 13:40:00 to 10-APR-13 13:40:00 (EST-5)
Location: RIDGWAY
Magnitude: 50.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

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

Thunderstorm Wind in CENTRE, PENNSYLVANIA
From 10-APR-13 18:53:00 to 10-APR-13 18:53:00 (EST-5)
Location: (UNV)UNIV PARK STATE
Magnitude: 58.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

UNV AWOS measured a peak thunderstorm wind gust of 67 mph at 23:53 UTC.

Thunderstorm Wind in LEBANON, PENNSYLVANIA
From 10-APR-13 20:07:00 to 10-APR-13 20:07:00 (EST-5)
Location: BORDNERSVILLE
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

KMUI ASOS measured a peak thunderstorm wind gust of 59 mph at 2107 EDT.

Thunderstorm Wind in LYCOMING, PENNSYLVANIA
From 10-APR-13 15:25:00 to 10-APR-13 15:25:00 (EST-5)
Location: HALLS
Magnitude: 50.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Thunderstorm winds estimated near 60 mph knocked down several trees and utility wires in and around the city of Williamsport. Wind damage was reported across Piatt, Old Lycoming, Hepburn, Muncy and Wolf Townships along with Hughesville and South Williamsport Boroughs.

Thunderstorm Wind in CLEARFIELD, PENNSYLVANIA
From 10-APR-13 18:15:00 to 10-APR-13 18:15:00 (EST-5)
Location: CLEARFIELD
Magnitude: 52.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: 911 Call Center

Thunderstorm winds estimated between 60-70 mph knocked down several trees in and around Clearfield.

Lightning in WARREN, PENNSYLVANIA
From 10-APR-13 08:45:00 to 10-APR-13 08:45:00 (EST-5)
Location: WARREN
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Lightning struck a county-owned building next to the Warren Hospital. Damage to the roof was limited to one small hole.

Hail in MIFFLIN, PENNSYLVANIA
From 10-APR-13 16:15:00 to 10-APR-13 16:15:00 (EST-5)
Location: YEAGERTOWN
Magnitude: 0.75 
Reported by: Emergency Manager

Penny-size hail (0.75 inch) reported in Yeagertown.

Thunderstorm Wind in CAMERON, PENNSYLVANIA
From 10-APR-13 14:00:00 to 10-APR-13 14:00:00 (EST-5)
Location: SIZERVILLE
Magnitude: 61.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Park/Forest Service

Thunderstorm winds estimated around 70 mph knocked down a swath of 75-100 trees in a heavily wooded area at the Sizerville State Park. The damage straddled the Cameron/Potter county line with most of the damage in Cameron County.