A major winter storm affected central and southeast Pennsylvania on the 19th and 20th. A lighter accumulating snow affected the Poconos. Snowfall averaged around 3 inches in the Poconos, 6 inches in the Lehigh Valley, 6 to 12 inches in Berks, Bucks and Upper Montgomery Counties and 12 to 23 inches in and around the rest of the local Philadelphia area.  The 23.2 inches of snow that fell at Philadelphia International Airport was the second heaviest single event snowfall on record and the heaviest ever for the month of December.
Snow began around 1 a.m. EST on the 19th around the Philadelphia area, but took about twelve hours for it to reach the Lehigh Valley and the Poconos. The snow fell at its heaviest between 10 a.m. EST and 10 p.m. EST with the most bands of heavy snow across extreme southeast Pennsylvania. The snow ended around 1 a.m. EST in Berks County, but did end until around 8 a.m. EST farther east along the Delaware River.
A 51-year-old man died of a stroke while he was shoveling the snow in Havertown (Delaware County). A snowmobiling accident claimed the life of a 28-year-old man and injured a 23-year-old woman in Quakertown (Bucks County).  About 2,000 homes and businesses lost power during the storm. About seventy percent of flights were cancelled on the 19th at Philadelphia International Airport. Those that were not, had delays up to six hours. Flight delays continued into the 21st. The Philadelphia Eagles' home game on the 20th was pushed back to 4 p.m. EST so the stadium could be cleared of the snow. The winter storm postponed many planned local and high school sporting events. It came at an inopportune time for retailers as the Saturday (the 19th) before Christmas is usually one of the busiest shopping days of the year. Many malls around the local Philadelphia area closed early. Many municipalities in the southeast part of the state declared states of emergency. Since this storm occurred on the weekend, the number of traffic accidents was down. But, U.S. Route 209 in Brodheadsville in Monroe County was closed because of an accident. AAA Mid Atlantic said that the volume of calls for a Saturday was 64 percent higher than normal; many were stranded motorists. Many school districts either closed schools or had two hour delayed openings on the 21st. Some churches cancelled services on the 20th. Trash pick-ups were also delayed.
Representative snowfall included 23.2 inches at the Philadelphia International Airport, 19.0 inches in Folcroft (Delaware County), 16.5 inches in Wynnewood (Montgomery County), 16.3 inches in Exton (Chester County), 16.0 inches in Drexel Hill (Delaware County), 15.0 inches in East Nantmeal (Chester County), 13.3 inches in Willow Grove (Montgomery County), 12.5 inches in Bensalem (Bucks County), 10.5 inches in the Somerton section of Philadelphia, 9.6 inches in Perkasie (Bucks County), 8.3 inches in Royersford (Montgomery County), 7.0 inches in Boyertown (Berks County), 6.0 inches in Forks Township (Northampton County), 5.6 inches at the Lehigh Valley International Airport, 5.1 inches in East Stroudsburg (Monroe County), 5.0 inches in Lehighton (Carbon County)
The nor'easter responsible for the winter storm formed in the western Gulf of Mexico on the morning of the 17th. It moved northeast along the northern Gulf of Mexico and was just south of Mobile, Alabama at sunrise on the 18th. From there it moved northeast and continued to intensify and reached Savannah, Georgia around 7 p.m. EST on the 18th, near Cape Hatteras, North Carolina at 7 a.m. EST on the 19th. It continued to move northeast on the 19th and into the 20th and by sunrise on the 20th was located about 400 miles east of Seaside Heights, New Jersey.

Heavy Snow in BERKS, PENNSYLVANIA
From 19-DEC-09 05:00:00 to 20-DEC-09 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in CHESTER, PENNSYLVANIA
From 19-DEC-09 03:00:00 to 20-DEC-09 05:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in BUCKS, PENNSYLVANIA
From 19-DEC-09 06:00:00 to 20-DEC-09 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in DELAWARE, PENNSYLVANIA
From 19-DEC-09 01:00:00 to 20-DEC-09 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in MONTGOMERY, PENNSYLVANIA
From 19-DEC-09 03:00:00 to 20-DEC-09 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in NORTHAMPTON, PENNSYLVANIA
From 19-DEC-09 13:00:00 to 20-DEC-09 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in PHILADELPHIA, PENNSYLVANIA
From 19-DEC-09 01:00:00 to 20-DEC-09 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CARBON, PENNSYLVANIA
From 19-DEC-09 12:00:00 to 20-DEC-09 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MONROE, PENNSYLVANIA
From 19-DEC-09 12:00:00 to 20-DEC-09 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in LEHIGH, PENNSYLVANIA
From 19-DEC-09 13:00:00 to 20-DEC-09 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter