A low pressure system developed over the northern Gulf Coast on the evening of November 29 and moved northeast into the Ohio Valley on November 30. This system deepened considerably as it reached western New York on December 1 before departing into eastern Canada that evening, ending snow across much of the region. As the low tracked northeast towards Pennsylvania on November 30, widespread rain overspread the area, transitioning to snow from west to east through the day. The transition took longer over portions of Northwest Pennsylvania, including the Erie area, where warmer air held on through the evening hours, preventing snow until the early hours of the 1st. Once the transition from rain to snow occurred overnight, snow was persistent with half inch to one inch per hour snowfall rates of dense, wet snow. Snow accumulation totals that occurred overnight from the 30th into the 1st were 3 to 8 inches of synoptic snowfall across Northwest Pennsylvania by Noon. This first round of snow caused considerable issues for the morning commute on December 1 with numerous vehicle incidents and schools were closed across the area. As the low departed to the northeast, the snow event transitioned to an efficient lake-enhanced snow event and snow bands focused on the traditional snow belt of Northwest Pennsylvania. Additional accumulations of 4 to 12 inches of new snow occurred during this phase of the event. In the end, widespread snow amounts of 8 to 20 inches fell across Northwest Pennsylvania with the maximum in southern Erie and northern Crawford counties. The highest snowfall measurement in Pennsylvania was 22.5 inches by a trained snow spotter near Corry in southeastern Erie County. The official snow total for the event at Erie International Airport was only 5.3 inches, as the immediate coastal areas of northern Erie County were spared from the heavy snow accumulations and impacts, largely due to the relatively warmer waters of Lake Erie. There was one indirect fatality due to the winter storm in Northwest Pennsylvania, when an elderly man in southwest Erie County died from injuries sustained in an automobile accident caused by unsafe road conditions in Elk Creek Township.

Winter Storm in SOUTHERN ERIE, PENNSYLVANIA
From 01-DEC-20 01:00:00 to 02-DEC-20 03:00:00 (EST-5)
Property damage: 150.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rain changed over to snow during the early morning hours of December 1 in Northwest Pennsylvania, as low pressure moved just east of the area. By daybreak, heavy, wet snow overspread the region with visibility dropping to one-quarter of a mile or less and snowfall rates up to one inch per hour. Travel was severely disrupted by this storm and several vehicle accidents occurred as heavy snow quickly accumulated on area roadways and any pre-treatment efforts were hampered by rain on November 30. Due to hazardous road conditions, a multi-vehicle accident occurred on State Route 18 in Elk Creek Township around 6:10 am on December 1. A 79-year-old man was killed in this accident and a younger male child was seriously injured. Due to the heavy, wet nature of the snow and only modest wind speeds of 10 to 15 mph, blowing and drifting snow was not a big issue during this event. However, snow easily collected on area trees, especially area evergreen trees, and the weight of the snow allowed for trees to fall onto area roads, power lines, and even some buildings. Schools and several businesses closed on December 1 and 2 due to the weather conditions. In the southern portions of Erie County, snowfall totals ranged from 8 to 22 inches of snow for the event. A peak total of 22.5 inches of snow was observed in Corry. Other selected snowfall totals include: 18 inches in Greenfield Township, 17.8 inches in Edinboro, 17.5 inches in North East Township, 17 inches in Summit Township, 15.2 inches in Union City, 13.2 inches in McKean, and 8.5 inches in Millcreek Township.

Winter Storm in CRAWFORD, PENNSYLVANIA
From 01-DEC-20 00:00:00 to 02-DEC-20 00:00:00 (EST-5)
Property damage: 100.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Rain changed over to snow during the early morning hours of December 1 in Northwest Pennsylvania, as low pressure moved just east of the area. By daybreak, heavy, wet snow overspread the region with visibility dropping to one-quarter of a mile or less and snowfall rates up to one inch per hour. Travel was severely disrupted by this storm and several vehicle accidents occurred as heavy snow quickly accumulated on area roadways and any pre-treatment efforts were hampered by rain on November 30. Due to the heavy, wet nature of the snow and only modest wind speeds of 10 to 15 mph, blowing and drifting snow was not a big issue during this event. However, snow easily collected on area trees, especially area evergreen trees, and the weight of the snow allowed for trees to fall onto area roads, power lines, and even some buildings. Schools and several businesses closed on December 1 and 2 due to the weather conditions. In Crawford County, snowfall totals ranged from 8 to 17 inches of snow for the event. A peak total of 17.2 inches of snow was observed near Conneaut Lake. Other selected snowfall totals include: 16.5 in Cambridge Springs, 16.3 inches in Meadville, 15.6 inches near Atlantic, 15.3 inches in Spring Township, 13 inches in Linesville, 9.4 inches in Titusville, and 8 inches northwest of Jamestown.