A winter storm produced a protracted mixture of snow, sleet and freezing rain across southeast Pennsylvania and Berks County and mainly just snow in the Lehigh Valley and the Poconos from the late morning of the 21st through the overnight of the 21st.  Snowfall averaged 3 to 6 inches throughout the area. In addition to the snow, an average of one to two tenths of an inch of ice (highest toward the Interstate 95 corridor) in Berks County and southeast Pennsylvania also accumulated. The hardest hit locations were along the Interstate 95 corridor in and around Philadelphia.  Travel was extremely difficult, especially during the second half of the afternoon and evening.
Precipitation started as snow throughout Eastern Pennsylvania around Noon EST on the 21st. In the Poconos precipitation remained as snow. In the Lehigh Valley, the snow fell briefly heavy at times during the early afternoon and briefly mixed with sleet. The snow ended during the pre-dawn hours on the 22nd. In Berks County, the snow changed to a wintry mix after Midnight EST on the 22nd and the precipitation ended toward dawn on the 22nd. In the Philadelphia northern suburbs, the snow fell briefly heavy at times during the afternoon of the 21st and then changed to sleet and freezing rain late in the evening of the 21st and ended as freezing rain toward dawn on the 22nd. In the local Philadelphia area, the snow (heavy at times during the afternoon) changed to sleet and then freezing rain during the first half of the evening on the 21st and then to plain rain late that evening. The rain ended around sunrise on the 22nd.
In Philadelphia, a ground stop was in effect for several hours at the Philadelphia International Airport. About 20 percent of the flights in and out of the airport were cancelled. In Montgomery County, a jack-knifed tractor-trailer forced the closure of the southbound Northeast Extension of the Pennsylvania Turnpike in Whitpain Township. State police were responding to numerous accidents in Chester and Delaware Counties. The speed limit on the Pennsylvania Turnpike, most other major interstates and highways in Eastern Pennsylvania and the Delaware River Bridges around Philadelphia was reduced. In southeast Pennsylvania, SEPTA reported that numerous bus routes were detoured and regional rail service experienced delays up to 30 minutes. In Chester County in Phoenixville, the weight of the snow and ice took down several trees and power lines and caused outages to several hundred residents. In the Lehigh Valley, there were also a flurry of cancellations and accidents. In Lehigh County, a 79-year-old man was badly injured in a two car accident on Schantz Road in Upper Macungie Township. In Northampton County, a vehicle drove into a tree in Lower Saucon Township. A side effect of all of the wintry weather was that several municipalities in Delaware County reported that residents complained about a salty taste to their drinking water.
Representative ice accumulations included 0.25 inches in Bala Cynwyd (Montgomery County), 0.20 inches and 0.15 inches within Philadelphia, 0.1 inch in Doylestown (Bucks County) and Pottstown and Montgomeryville (Montgomery County), 0.06 inches in Spring City (Chester County) and .03 inches in Reading (Berks County).

Representative snowfall included 6.0 inches in Ridley Park (Delaware County), 5.5 inches in Danielsville (Northampton County), 5.2 inches in Nottingham (Chester County), 5.0 inches in Perkasie (Bucks County), 4.8 inches at the Philadelphia International Airport, 4.6 inches in Salisbury Township (Lehigh County), 4.5 inches in Jenkintown (Montgomery County) 4.4 inches in Kennett Square (Chester County), Wyndmoor (Philadelphia) and Wynnewood (Montgomery County), 4.3 inches in Albrightsville (Carbon County) and Springtown (Bucks County), 4.0 inches in Reading  and Hamburg (Berks County), Glendon (Northampton County) and Schnecksville (Lehigh County), 3.9 inches in Ross Township (Monroe County), 3.8 inches in Quakertown (Bucks County) and the Lehigh Valley International Airport, 3.7 inches in Martins Creek (Northampton County), 3.6 inches in Kutztown (Berks County), 3.5 inches in Palmerton (Carbon County), 3.3 inches in Furlong (Bucks County),  3.2 inches in Royersford (Montgomery County), 3.1 inches in Gilbertsville (Montgomery County), 3.0 inches in Thorndale and West Chester (Chester County) and Doylestown (Bucks County), 2.8 inches in East Stroudsburg (Monroe County) and 2.5 inches in Pocono Summit (Monroe County).
The winter storm was caused by a low pressure system that moved northeast from the southern Mississippi River Valley on the morning of the 21st, to the Tennessee River Valley on the early evening of the 21st, into south central Pennsylvania early on the 22nd and then rapidly reached the Canadian Maritimes on the morning of the 22nd. In spite of the surface high pressure system being offshore (in an unfavorable position normally for snow) at the onset of the event, the combination of extremely cold antecedent conditions and a relatively weak low pressure system (made it more difficult to remove cold air near the surface) still caused a winter weather event in Eastern Pennsylvania.

Winter Storm in PHILADELPHIA, PENNSYLVANIA
From 21-FEB-15 12:00:00 to 22-FEB-15 00:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in DELAWARE, PENNSYLVANIA
From 21-FEB-15 12:00:00 to 22-FEB-15 00:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Winter Storm in EASTERN CHESTER, PENNSYLVANIA
From 21-FEB-15 11:30:00 to 22-FEB-15 01:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Winter Storm in EASTERN MONTGOMERY, PENNSYLVANIA
From 21-FEB-15 12:00:00 to 22-FEB-15 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Storm in LOWER BUCKS, PENNSYLVANIA
From 21-FEB-15 12:00:00 to 22-FEB-15 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

Winter Weather in BERKS, PENNSYLVANIA
From 21-FEB-15 11:00:00 to 22-FEB-15 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in LEHIGH, PENNSYLVANIA
From 21-FEB-15 11:30:00 to 22-FEB-15 05:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in NORTHAMPTON, PENNSYLVANIA
From 21-FEB-15 12:00:00 to 22-FEB-15 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in UPPER BUCKS, PENNSYLVANIA
From 21-FEB-15 12:00:00 to 22-FEB-15 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN MONTGOMERY, PENNSYLVANIA
From 21-FEB-15 11:30:00 to 22-FEB-15 06:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in WESTERN CHESTER, PENNSYLVANIA
From 21-FEB-15 11:00:00 to 22-FEB-15 02:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: CoCoRaHS

Winter Weather in MONROE, PENNSYLVANIA
From 21-FEB-15 11:30:00 to 22-FEB-15 03:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Winter Weather in CARBON, PENNSYLVANIA
From 21-FEB-15 11:00:00 to 22-FEB-15 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter