A major winter storm dropped 20 to 30 inches of snow from Philadelphia south in Eastern Pennsylvania, 10 to 20 inches across the northern Philadelphia suburbs, 6 to 12 inches across Berks County and the Lehigh Valley and less than 6 inches in the Poconos from  the late afternoon of the 5th into the afternoon of the 6th. The 28.5 inches of snow that fell in Philadelphia became the second highest single snowfall event on history, only surpassed by the 30.7 inches of snow that fell during the Blizzard of January 1996.
Snow spread from south to north across Eastern Pennsylvania from late in the afternoon on the 5th into the middle of the evening of the 5th. The snow fell heavy at times during the first half of the day on the 6th across southeast Pennsylvania and Berks County. The snow ended during the morning of the 6th in the Lehigh Valley, Berks County and the Poconos and during the afternoon of the 6th in southeast Pennsylvania.
Pennsylvania Governor Ed Rendell declared a statewide disaster emergency. Many county and municipalities declared their own snow emergencies. National Guard troops were deployed to assist the State Police. Many roads and highways in southeastern Pennsylvania were impassable. Speed limits were reduced on the Delaware River bridges. Amtrak canceled train service. The SEPTA regional rail and bus lines suspended service on the 6th in and around Philadelphia. Airlines canceled flights in and out of Philadelphia International Airport on the 6th. They resumed on the 7th. Many businesses, stores and malls were closed on the 6th. Events were canceled or postponed. Philadelphia schools were closed on Monday the 8th. Where the snow was relatively lighter, numerous accidents and fender benders were reported in Berks County and the Lehigh Valley. In Berks County, several suspected heart attacks from shoveling snow occurred. A head-on collision in Cumru Township caused an injury. In West Lawn, a pedestrian was injured after he was struck by a vehicle and tossed from Westbound U.S. Route 422 onto Penn Avenue.  The snow was relatively fluffy and caused very few power outages. PECO Energy reported only 200 homes and businesses lost power in Bucks and Montgomery Counties.
Representative snowfall included 29.5 inches in Folcroft and Newtown Square (Delaware County), 28.5 inches at the Philadelphia International Airport, 25.5 inches in Drexel Hill (Delaware County), 23.0 inches in New London (Chester County) and Wynnewood (Montgomery County), 22.0 inches in the Roxborough (Philadelphia County), 20.0 inches in Norristown (Montgomery County), 18.3 inches in East Nantmeal (Chester County), 15.0 inches in Langhorne (Bucks County) and Gilbertsville (Montgomery County), 11.0 inches in Fleetwood (Berks County), 10.5 inches in Doylestown (Bucks County), 7.7 inches at the Lehigh Valley International Airport, 4.0 inches in Lehighton (Carbon County) and 1.0 inch in Pocono Summit (Monroe County).
The winter storm was caused by a low pressure system that moved west to east across northern Mexico and emerged in the Gulf of Mexico near Brownsville, Texas on the morning of the 4th. The low pressure system moved east and was located near New Orleans, Louisiana at 7 p.m. EST on the 4th and Mobile, Alabama at 7 a.m. EST on the 5th. The low pressure system then started to move northeast and was near Wilmington, North Carolina at 7 p.m. EST on the 5th; Elizabeth City, North Carolina at 1 a.m. EST on the 6th; the Virginia coastal waters at 7 a.m. EST on the 6th and then drifted slowly east off the lower Delmarva Peninsula the rest of the day on the 6th. The storm track was perfect for heavy snow in southeastern Pennsylvania, but became less favorable (too far southeast) for places farther to the north.

Winter Storm in NORTHAMPTON, PENNSYLVANIA
From 05-FEB-10 22:00:00 to 06-FEB-10 10:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CARBON, PENNSYLVANIA
From 05-FEB-10 22:00:00 to 06-FEB-10 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in PHILADELPHIA, PENNSYLVANIA
From 05-FEB-10 18:00:00 to 06-FEB-10 16:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BUCKS, PENNSYLVANIA
From 05-FEB-10 19:00:00 to 06-FEB-10 13:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MONROE, PENNSYLVANIA
From 05-FEB-10 22:00:00 to 06-FEB-10 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in DELAWARE, PENNSYLVANIA
From 05-FEB-10 17:00:00 to 06-FEB-10 16:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in CHESTER, PENNSYLVANIA
From 05-FEB-10 17:00:00 to 06-FEB-10 15:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in MONTGOMERY, PENNSYLVANIA
From 05-FEB-10 17:00:00 to 06-FEB-10 14:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BERKS, PENNSYLVANIA
From 05-FEB-10 17:00:00 to 06-FEB-10 12:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in LEHIGH, PENNSYLVANIA
From 05-FEB-10 22:00:00 to 06-FEB-10 10:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter