A wintry mix of sleet and freezing rain fell from the late evening of the 23rd into the morning on the 24th across eastern Pennsylvania. The resulting glaze on untreated roadways led to numerous accidents. Precipitation was spottier right around the local Philadelphia area, but was steadier elsewhere. Ice accretions in Philadelphia and the nearby northwest suburbs averaged around one tenth of an inch while ice accretions across Berks County, the Lehigh Valley and the Poconos averaged around two-tenths of an inch. In Philadelphia and its nearby suburbs, precipitation started as sleet before Midnight EST on the 23rd and changed to freezing rain by 3 a.m. EST. In Berks County, the Lehigh Valley and the Poconos, precipitation started briefly as sleet between 1 a.m. and 3 a.m. EST and changed quickly to freezing rain. Temperatures continued to rise that morning and between 7 a.m. and 10 a.m. EST, the freezing rain changed to plain rain. The change took the longest in the Poconos. The recent unseasonably cold weather made it easier for slippery conditions to develop on untreated roadways. Many serious accidents were reported as many vehicles slid off roadways or into oncoming or stopped traffic.
In Carbon County, a 29-year-old man was killed in a head-on collision with a plow truck on Pennsylvania State Route 903 in Penn Forest Township. In Monroe County, three rapid accidents occurred with the start of the freezing rain on Pennsylvania State Route 402 in Middle Smithfield Township.
Near the Northampton/Lehigh County border, a 47-year-old man died after his minivan crashed into a tractor-trailer that was already stopped for another accident on Eastbound Interstate 78 near Hellertown. Multiple pre-dawn accidents closed a four mile stretch of Eastbound Interstate 78 for seven hours from 330 a.m. EST through 1030 a.m. EST. One westbound lane of Interstate 78 was also closed for three hours because of an overturned tractor-trailer. In Northampton County, in Williams Township, Pennsylvania State Route 611 was closed after a vehicle slid into an embankment.
In Berks County, sections of U.S. Route 222 were closed in Maxatawny and Cumru Townships. A multi-vehicle accident closed Pennsylvania State Route 73 in Ruscombmanor Township. In addition several people were hurt after slipping on icy sidewalks and driveways.
Within the city of Philadelphia, a twenty-two vehicle crash that involved a bus and a tractor-trailer closed the Passyunk Avenue Bridge for several hours. There was also a ten vehicle accident on a southbound exit ramp of Interstate 95. There was a separate five vehicle accident on Interstate 95 itself and a six vehicle accident in the East Falls section of the city. In the northwest suburbs, parts of the Pennsylvania Turnpike and ramps to and from Interstates 76 and 476 were intermittently closed because of accidents and/or icy conditions. The Schuylkill Expressway, U.S. Route 422 and State Routes 30 and 3 were all adversely affected. An accident with an injury occurred in Hatfield (Montgomery County). Pennsylvania State Route 309 was closed because of a jack-knifed tractor trailer between Hilltown and Perkasie in Bucks County.
The freezing rain and sleet was caused by a low pressure system and its approaching warm front. Precipitation developed preceding the warm front. An arctic high pressure system left enough cold air near the surface for precipitation to start as sleet and freezing rain.

Winter Weather in PHILADELPHIA, PENNSYLVANIA
From 23-DEC-08 22:00:00 to 24-DEC-08 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MONTGOMERY, PENNSYLVANIA
From 23-DEC-08 23:00:00 to 24-DEC-08 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in BUCKS, PENNSYLVANIA
From 23-DEC-08 23:00:00 to 24-DEC-08 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in BERKS, PENNSYLVANIA
From 24-DEC-08 02:00:00 to 24-DEC-08 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in LEHIGH, PENNSYLVANIA
From 24-DEC-08 02:00:00 to 24-DEC-08 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in NORTHAMPTON, PENNSYLVANIA
From 24-DEC-08 02:00:00 to 24-DEC-08 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CARBON, PENNSYLVANIA
From 24-DEC-08 02:00:00 to 24-DEC-08 10:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MONROE, PENNSYLVANIA
From 24-DEC-08 02:00:00 to 24-DEC-08 10:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CHESTER, PENNSYLVANIA
From 23-DEC-08 22:00:00 to 24-DEC-08 10:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in DELAWARE, PENNSYLVANIA
From 23-DEC-08 22:00:00 to 24-DEC-08 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter