A winter storm dropped heavy snow in the Poconos and Lehigh Valley and a mixture of heavy snow with some sleet and freezing rain in Berks County and the far northern Philadelphia suburbs from the evening of the 23rd into the morning of the 24th. Less wintry precipitation (a faster switch to rain) occurred progressively closer to Philadelphia. Snowfall averaged 6 to 9 inches from Upper Bucks County northward through the Lehigh Valley, Berks County and the Poconos; 2 to 5 inches across the remaining Philadelphia suburbs and 1 to 2 inches within Philadelphia.  Ice accumulations were generally just a trace.  At the height of the storm, one inch hourly snowfall rates were common.
The snow caused traveling difficulties as well as postponement of social activities on the 24th.  In Berks County, a weather related crash on U.S. Route 222 in Spring Township near Broadcasting Road closed the roadway for one hour.  Also the snow caused power outages to about 100 Metropolitan Edison customers in the county.  Some snow emergencies were declared in the Philadelphia northwest suburbs.  Northampton County Community College postponed its graduation.  Speed restrictions were also in place on all of the major bridges crossing the Delaware River in and around Philadelphia. Philadelphia International Airport instituted a ground stop program. About 24 flights were cancelled on the day and delays averaged 40 minutes.
Precipitation started as snow on the evening of the 23rd throughout Eastern Pennsylvania from south to north between 8 p.m. EST and Midnight EST.  In the Poconos and Lehigh Valley, the snow fell at its heaviest during the pre-dawn hours on the 24th and ended between 8 a.m. EST and 9 a.m. EST on the 24th. In the Philadelphia northern suburbs and Berks County, the snow changed to freezing rain (with some sleet) between 3 a.m. EST and 6 a.m. EST on the 24th. Precipitation ended as the freezing mixture between 7 a.m. EST and 8 a.m. EST on the 24th. In the immediate Philadelphia area including Chester County, the snow changed to rain between 2 a.m. EST and 5 a.m. EST on the 24th and remained rain until it ended around 8 a.m. EST on the 24th.
Representative snowfall included 9.0 inches in Coolbaugh Township (Monroe County), 8.0 inches in Huffs Church (Berks County) and Forks Township (Northampton County), 7.9 inches at the Lehigh Valley International Airport, 7.3 inches in Martins Creek (Northampton County), 7.0 inches in West Rockhill Township (Bucks County), Nazareth (Northampton County) and Albrightsville (Carbon County), 6.5 inches in Schnecksville (Lehigh County), 6.3 inches in Stroudsburg (Monroe County), 6.0 inches in Shillington (Berks County), 5.5 inches in Gilbertsville (Montgomery County), 5.1 inches in Reading (Berks County) and Lehighton (Carbon County),  4.5 inches in East Nantmeal Township (Chester County), 4.2 inches in Langhorne (Bucks County), 4.0 inches in Horsham (Montgomery County), 3.7 inches in Spring City (Chester County), 3.0 inches in Chadds Ford (Delaware County), 2.5 inches in Fort Washington (Montgomery County), 2.0 inches in Fox Chase (Philadelphia) and Penndel (Bucks County), 1.6 inches in Concord (Delaware County) and 1.0 inch at the Philadelphia International Airport.
The winter storm was caused by a low pressure system which moved along the northern Gulf of Mexico on the evening of the 22nd through the morning of the 23rd. It then started to track to the northeast and was in southeast Alabama on the afternoon of the 23rd and moved through southern Georgia overnight on the 23rd. A second low pressure system formed on its warm front that same night in South Carolina. This would become the primary low pressure system as it too tracked to the northeast.  At 1 a.m. EST on the 24th, it was located near Norfolk, Virginia, 7 a.m. EST on the 24th over the Delmarva coastal waters as it started to intensify rapidly. At 1 p.m. EST on the 24th, the low pressure system was already southeast of Long Island, New York and would pass near Nantucket, Massachusetts later that afternoon.

Winter Weather in DELAWARE, PENNSYLVANIA
From 23-JAN-15 20:30:00 to 24-JAN-15 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in PHILADELPHIA, PENNSYLVANIA
From 23-JAN-15 20:30:00 to 24-JAN-15 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in LEHIGH, PENNSYLVANIA
From 23-JAN-15 23:00:00 to 24-JAN-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in NORTHAMPTON, PENNSYLVANIA
From 23-JAN-15 23:00:00 to 24-JAN-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Heavy Snow in CARBON, PENNSYLVANIA
From 23-JAN-15 23:00:00 to 24-JAN-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Heavy Snow in MONROE, PENNSYLVANIA
From 23-JAN-15 23:00:00 to 24-JAN-15 09:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in BERKS, PENNSYLVANIA
From 23-JAN-15 22:00:00 to 24-JAN-15 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Storm in UPPER BUCKS, PENNSYLVANIA
From 23-JAN-15 22:00:00 to 24-JAN-15 08:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in WESTERN CHESTER, PENNSYLVANIA
From 23-JAN-15 20:00:00 to 24-JAN-15 04:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Winter Weather in EASTERN CHESTER, PENNSYLVANIA
From 23-JAN-15 20:00:00 to 24-JAN-15 04:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in WESTERN MONTGOMERY, PENNSYLVANIA
From 23-JAN-15 21:30:00 to 24-JAN-15 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in EASTERN MONTGOMERY, PENNSYLVANIA
From 23-JAN-15 21:30:00 to 24-JAN-15 04:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in LOWER BUCKS, PENNSYLVANIA
From 23-JAN-15 22:00:00 to 24-JAN-15 05:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter