One to four inches of snow accumulated across Eastern Pennsylvania during the afternoon and evening of the 17th before it changed to rain. Precipitation though changed to freezing rain in the Poconos. The snow coincided with the evening commute and made for what was described as a wicked homeward commute.
Snow began falling across Eastern Pennsylvania between Noon EST and 3 p.m. EST. It spread from west to east across the area and started the latest in Bucks and Northampton Counties. As warmer air moved in aloft, the snow changed to rain around 6 p.m. EST in the local Philadelphia area, but took as late as 9 p.m. EST to change to rain in some of the Philadelphia northern suburbs as well as in Berks County and the Lehigh Valley. The rain ended overnight. In the Poconos, the precipitation changed to freezing rain after Midnight EST on the 18th and ended as freezing rain around 6 a.m. EST on the 18th. In addition to the snow, ice accretions averaged around one-tenth of an inch in the Poconos.
Many of the traffic related problems were in the Philadelphia northwest suburbs and Berks County.  In Chester County, in Downingtown, a school bus driver lost control on Marshall Road and slid into an embankment and overturned. The 55-year-old woman driver suffered back and neck injuries while a student had back and arm pain. Marshall Road was closed for three hours. Traffic accidents in the county caused closures of sections of Pennsylvania State Routes 52 and 82 as well as Marshalton-Thorndale Road. Accidents were reported in over half a dozen municipalities in the county. In Berks County, so many accidents occurred between 4 p.m. EST and 6 p.m. EST that roads were closed until they could be treated. Sections of Pennsylvania State Routes 61, 100 and 183 were closed. Interstate 78 traffic just crawled along. Between 6 p.m. and 8 p.m. EST so many people were already injured in Reading that ambulances were diverted to other hospitals. There were twenty accidents alone in Reading. Dozens of vehicles became stuck in the snow. The worst reported accident was a pickup truck which rolled over on Oysterdale Road in Pike Township.
In Montgomery County, dozens of vehicles slid off roads. In Bucks County, seventy-two accidents were reported by 6 p.m. EST, mostly minor fender benders from vehicles sliding off roads. In Philadelphia, there were numerous airport delays at the International Airport. In Carbon County, a school bus became stuck on the snow covered Sammels Hill just south of Pennsylvania State Route 443 in Mahoning Township.
Actual accumulations included 3.7 inches in Glenmoore (Chester County), 3.5 inches in Fredericksville (Berks County) and East Nantmeal (Chester County), 3.3 inches in Williams Township (Northampton County), 3.0 inches in Stroudsburg (Monroe County) and Rosemont (Montgomery County), 2.9 inches in Coatesville (Chester County), 2.8 inches in Morgantown (Berks County), 2.5 inches in Perkasie (Bucks County), Bossardsville (Monroe County) and Drexel Hill (Delaware County), 2.4 inches at the Lehigh Valley International Airport and Forks Township (Northampton County), 2.3 inches in West Chester (Chester County) and Royersford (Montgomery County), 2.1 inches in Macungie (Lehigh County), 1.5 inches at Beltzville Lake (Carbon County) and Wynnewood (Montgomery County), 1.2 inches in Doylestown (Bucks County) and 1.0 inch at the Philadelphia International Airport and Neshaminy Falls (Bucks County).
The precipitation was caused by a low pressure system that moved northeast from Florida early in the morning on the 17th to near Myrtle Beach, South Carolina at 1 p.m. EST on the 17th, Cape Hatteras, North Carolina at 7 p.m. EST on the 17th, just east of Wallops Island, Virginia at 1 a.m. EST on the 18th and eastern Long Island, New York at 7 a.m. EST on the 18th. The surface high pressure system was already east of the region before the precipitation arrived and the position made it tough for the cold air to remained locked in near the surface. The only place where temperatures remained below freezing was the Poconos.

Winter Weather in CHESTER, PENNSYLVANIA
From 17-JAN-08 12:00:00 to 17-JAN-08 19:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in DELAWARE, PENNSYLVANIA
From 17-JAN-08 13:00:00 to 17-JAN-08 18:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in PHILADELPHIA, PENNSYLVANIA
From 17-JAN-08 13:00:00 to 17-JAN-08 18:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in BERKS, PENNSYLVANIA
From 17-JAN-08 13:00:00 to 17-JAN-08 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MONTGOMERY, PENNSYLVANIA
From 17-JAN-08 13:00:00 to 17-JAN-08 20:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in BUCKS, PENNSYLVANIA
From 17-JAN-08 14:00:00 to 17-JAN-08 21:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in LEHIGH, PENNSYLVANIA
From 17-JAN-08 14:00:00 to 17-JAN-08 21:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in NORTHAMPTON, PENNSYLVANIA
From 17-JAN-08 14:00:00 to 17-JAN-08 21:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CARBON, PENNSYLVANIA
From 17-JAN-08 12:00:00 to 18-JAN-08 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MONROE, PENNSYLVANIA
From 17-JAN-08 12:00:00 to 18-JAN-08 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter