A vigorous cold front and a rapidly intensifying low pressure system east of the Delmarva Peninsula combined to drop 1 to 4 inches of snow across most of Eastern Pennsylvania from the morning on the 14th into the early morning on the 15th. Snow fell moderate to heavy at times during the evening. Coupled with rapidly falling temperatures, the snow made for hazardous driving conditions on untreated roadways on this Valentine's Day.
The snow started close to sunrise on the 14th in the Poconos, the late morning in Berks County and the Lehigh Valley and around Noon EST in the local Philadelphia area. Precipitation fell in bands, so there were breaks in the snow heading into the evening. The heaviest band of snow preceded and accompanied the cold frontal passage itself during the evening.  Snowfall rates during this band easily reached one to two inches per hour.  Lighter snow fell overnight, but clean-up was complicated by increasingly stronger winds. The snow ended during the pre-dawn hours on the 15th. Numerous accidents were reported.
The snow caused the cancellation of some flights at the Philadelphia International Airport. Speed limits on Delaware River bridges in and around Philadelphia as well as on all major interstates and highways in Eastern Pennsylvania were reduced.  SEPTA Regional Rail Service reported delays.
Representative snowfall included 4.2 inches in Furlong (Bucks County), 4.0 inches in Lower Makefield Township (Bucks County) and Forks Township (Northampton County), 3.7 inches in Saylorsburg (Monroe County), 3.3 inches in Doylestown (Bucks County), 3.0 inches in Jim Thorpe (Carbon County) and Glendon (Northampton County), 2.8 inches in Glenmoore (Chester County) and Nazareth (Northampton County), 2.6 inches in Bowmanstown (Carbon County), 2.5 inches in Sellersville (Bucks County) and Garnet Valley (Delaware County),  2.4 inches at the Lehigh Valley International Airport and Graterford (Montgomery County), 2.3 inches in Bushkill Township (Northampton County), 2.0 inches in Penndel (Bucks County) and Pocono Summit (Monroe County), 1.8 inches in Huffs Church (Berks County), 1.7 inches in Royersford (Montgomery County), 1.6 inches in Mohnton (Berks County), 1.3 inches in Alburtis (Lehigh County),Wynnewood (Montgomery County) and the Philadelphia International Airport, 1.2 inches in Hamburg (Berks County) and 1.0 inch in West Chester (Chester County).
The snow was caused by a strong cold front that moved from Lake Erie on the morning of the 14th rapidly southeast and crossed the Pennsylvania Allegheny Mountains during the middle of the afternoon on the 14th. A new low pressure system was forming on this front and at 7 p.m. EST as the front moved through the Susquehanna Valley and western Maryland, a 996 millibar low pressure system was intensifying near Washington, D.C. The cold front and the low pressure system then quickly crossed the state and at 10 p.m. EST that evening, the front and 994 millibar low pressure system were off the Delaware coast. The upper air low pressure system passed through Pennsylvania overnight and this helped prolong the snow longer.  At 7 a.m. EST the following morning, a 978 millibar surface low pressure system was occluding south of Nantucket, Massachusetts.

Winter Weather in EASTERN CHESTER, PENNSYLVANIA
From 14-FEB-15 12:00:00 to 15-FEB-15 01:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in WESTERN MONTGOMERY, PENNSYLVANIA
From 14-FEB-15 12:30:00 to 15-FEB-15 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in EASTERN MONTGOMERY, PENNSYLVANIA
From 14-FEB-15 12:30:00 to 15-FEB-15 01:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in UPPER BUCKS, PENNSYLVANIA
From 14-FEB-15 12:30:00 to 15-FEB-15 04:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in LOWER BUCKS, PENNSYLVANIA
From 14-FEB-15 13:00:00 to 15-FEB-15 04:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in PHILADELPHIA, PENNSYLVANIA
From 14-FEB-15 13:00:00 to 15-FEB-15 01:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in DELAWARE, PENNSYLVANIA
From 14-FEB-15 13:00:00 to 15-FEB-15 01:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in MONROE, PENNSYLVANIA
From 14-FEB-15 07:00:00 to 15-FEB-15 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CARBON, PENNSYLVANIA
From 14-FEB-15 07:00:00 to 15-FEB-15 07:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in BERKS, PENNSYLVANIA
From 14-FEB-15 11:00:00 to 14-FEB-15 23:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in LEHIGH, PENNSYLVANIA
From 14-FEB-15 11:00:00 to 15-FEB-15 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in NORTHAMPTON, PENNSYLVANIA
From 14-FEB-15 11:00:00 to 15-FEB-15 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN CHESTER, PENNSYLVANIA
From 14-FEB-15 12:00:00 to 15-FEB-15 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter