A slowly westward moving backdoor cold front produced strong to severe thunderstorms across Eastern Pennsylvania during the afternoon and evening of the 27th.

Hail in BERKS, PENNSYLVANIA
From 27-MAY-10 17:30:00 to 27-MAY-10 17:30:00 (EST-5)
Location: FREDERICKSVILLE
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Quarter to ping pong ball size hail fell from a severe thunderstorm in Rockland Township.

Thunderstorm Wind in NORTHAMPTON, PENNSYLVANIA
From 27-MAY-10 13:20:00 to 27-MAY-10 13:20:00 (EST-5)
Location: ROSETO
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm knocked down a few trees in Roseto Borough. Small hail also fell during the thunderstorm.

Hail in NORTHAMPTON, PENNSYLVANIA
From 27-MAY-10 14:19:00 to 27-MAY-10 14:20:00 (EST-5)
Location: GLENDON
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Golf ball size hail fell from a severe thunderstorm in Williams Township. Nickel to Quarter size hail also fell in nearby Glendon Borough.

Hail in LEHIGH, PENNSYLVANIA
From 27-MAY-10 16:51:00 to 27-MAY-10 16:51:00 (EST-5)
Location: FOGELSVILLE
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Nickel size hail fell in Fogelsville.

Hail in BUCKS, PENNSYLVANIA
From 27-MAY-10 14:50:00 to 27-MAY-10 14:50:00 (EST-5)
Location: FERNDALE
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Penny size hail fell in Ferndale (Nockamixon Township).

Hail in MONTGOMERY, PENNSYLVANIA
From 27-MAY-10 16:50:00 to 27-MAY-10 17:00:00 (EST-5)
Location: POTTSTOWN
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail fell in Pottstown.

Hail in CHESTER, PENNSYLVANIA
From 27-MAY-10 16:53:00 to 27-MAY-10 17:00:00 (EST-5)
Location: CEDARVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail fell along the Chester and Montgomery County line.

Hail in CHESTER, PENNSYLVANIA
From 27-MAY-10 17:07:00 to 27-MAY-10 17:07:00 (EST-5)
Location: SPRING CITY
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Quarter size hail from a severe thunderstorm fell in Spring City.

Lightning in MONROE, PENNSYLVANIA
From 27-MAY-10 17:20:00 to 27-MAY-10 17:20:00 (EST-5)
Location: EAST STROUDSBURG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Multiple lightning strikes damaged transformers in and around East Stroudsburg.

Hail in MONTGOMERY, PENNSYLVANIA
From 27-MAY-10 18:09:00 to 27-MAY-10 18:10:00 (EST-5)
Location: POTTSTOWN
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The second severe thunderstorm of the day dropped nickel to ping pong ball size hail in and around Pottstown.

Hail in CHESTER, PENNSYLVANIA
From 27-MAY-10 18:45:00 to 27-MAY-10 18:55:00 (EST-5)
Location: DOWNINGTOWN
Magnitude: 0.88 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Hail as large as nickels fell for approximately ten minutes in East Caln Township.

Hail in LEHIGH, PENNSYLVANIA
From 27-MAY-10 16:11:00 to 27-MAY-10 16:11:00 (EST-5)
Location: GERMANSVILLE
Magnitude: 1.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

A severe thunderstorm dropped quarter size hail in Heidelberg Township.

Hail in BERKS, PENNSYLVANIA
From 27-MAY-10 19:50:00 to 27-MAY-10 19:50:00 (EST-5)
Location: MUHLENBERG PARK
Magnitude: 0.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Dime to penny size hail fell in Muhlenberg Township. The same thunderstorm produced estimated wind gusts to 50 mph.

Hail in BERKS, PENNSYLVANIA
From 27-MAY-10 17:13:00 to 27-MAY-10 17:13:00 (EST-5)
Location: HENNINGSVILLE
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SHAVE Project

Quarter to golf ball size hail fell from a severe thunderstorm in Longswamp Township.