Winter Storm and Sleet in Pennsylvania, February 25, 2001

A cold front moved through Eastern Pennsylvania on the 23rd. A large high pressure system build into the region that night and on the 24th. Meanwhile a rather intense low pressure system was located over the foothills of the Rockies on the morning of the 24th. It moved into the western Great Lakes the morning of the 25th as the high pressure system moved east to the Canadian Maritimes. While the low pressure system was intense, it was located too far west to quickly scour the cold air that was left across most of Eastern Pennsylvania. Precipitation started as sleet and freezing rain across the Poconos, Berks County, the Lehigh Valley and the far northern Philadelphia suburbs. By 9 a.m. EST enough warm air had arrived for the precipitation to change to plain rain from the Lehigh Valley south. Ice accretions were generally less than one tenth of an inch. Farther to the north, it took longer for the warm air to move in near the surface and freezing rain persisted until around Noon EST in the Poconos. By then between .15 and .30 of an inch of ice accrued on exposed surfaces (such as trees and power lines). Lesser amounts accrued on roadways, but untreated roads and walks were extremely hazardous. Since this event occurred on a Sunday morning, the number of traffic accidents were less than would have occurred on a weekday morning.