Winter Storm and Sleet in Pennsylvania, March 4 to 7, 2001

An intensifying low pressure system brought a protracted wintry mix of precipitation to Eastern Pennsylvania on the 4th and 5th and to the Poconos through the 6th. Precipitation began as rain across extreme southeast Pennsylvania around daybreak on the 4th. Farther to the north as a high pressure system built into northern New England, precipitation spread as light snow through the rest of the morning into the Poconos. As precipitation intensity increased during the day, sleet and snow began to mix in around the Philadelphia area. As evening arrived, while warm air was moving in aloft, the northeast winds around the surface low pressure system to the south and the high pressure system over eastern New England, not only anchored the cold air in place, but started moving it southward. This continued a mixture of rain, freezing rain, sleet and snow through the night across extreme Southeast Pennsylvania. Farther to the north, precipitation changed to sleet and then freezing rain. This began during the early evening in the northern Philadelphia suburbs, late in the evening across Berks County and the Lehigh Valley and after midnight in the Poconos. Toward daybreak on the 5th, cold air began moving in at all levels. This changed the rain to freezing rain in all areas of southeast Pennsylvania. Elsewhere precipitation changed to all snow. The change to all snow also spread across extreme southeast Pennsylvania around noon EST. The snow ended during the second half of the afternoon and during the early evening of the 5th across Eastern Pennsylvania. As the low retrograded a bit on Tuesday the 6th, steadier snow moved into the Poconos overnight on the 5th and persisted into the 6th. Elsewhere, the snow intensity was considerably lighter and fell mainly during the daytime of the 6th.Throughout this event, ground temperatures were relatively warm across southeastern Pennsylvania and the snow had a difficult time accumulating, especially before nightfall on the 4th. Elsewhere, the change to sleet and snow compacted the accumulations. Total accumulations ranged from around one inch in the Philadelphia area, to around six inches in the Lehigh Valley and to around one foot in the Poconos. About one quarter to one third of an inch of ice accrued on exposed surfaces during the night of the 4th and morning of the 5th across the northern Philadelphia suburbs.There were numerous minor accidents across the area. Many motorists were stranded in the Poconos. The one reported traffic fatality occurred on the 5th in Coolbaugh Township (Monroe County). A 54-year-old woman was killed when the driver of the vehicle on Pennsylvania State Route 611 lost control and struck a utility pole. In Monroe County, Interstate 80 was also closed for one hour because of a tractor trailer accident near Stroudsburg. Many businesses and schools were closed on the 5th. Schools around Philadelphia dismissed children early as the precipitation changed to snow on the 5th. Snow emergencies were declared by many municipalities. Many flights were cancelled from Lehigh Valley International Airport. Some schools were also closed on the 6th, but most just had delayed openings. Specific accumulations included 14 inches in Tobyhanna (Monroe County), 11 inches in Pocono Summit (Monroe County), 8 inches in Saylorsburg (Monroe County), 6.5 inches in Penn Forest Township (Carbon County), 6.2 inches in East Stroudsburg (Monroe County), 6 inches in Schnecksville (Lehigh County), 5.5 inches in Jim Thorpe (Carbon County), 5.3 inches in Bath (Northampton County), 4.6 inches in Springtown (Bucks County), 4 inches in Easton (Northampton County), Palm (Montgomery County) and Southampton (Bucks County), 3.4 inches in Honey Brook (Chester County), 3 inches in Sellersville and Doylestown (Bucks County), 2 inches in Morgantown and Reading (Berks County), 1.8 inches in Crum Creek (Delaware County) and 1 inch at the Philadelphia International Airport. The low pressure system developed over the western Gulf of Mexico on the 3rd. By the morning of the 4th, the surface low had moved northeast into eastern Tennessee. The low continued to move northeast and was over the Delmarva coastal waters on the morning of the 5th. It then began to intensify as it moved toward Cape Cod. The later intensification prevented heavier snow from occurring farther to the south with this system. An upper level low then captured the surface system and dragged it westward (retrograded) toward the coast on the 6th before it headed east for good on the 7th.