Winter Storm — Southern Erie, Pennsylvania

2020-12-24 to 2020-12-26 · Southern Erie, Pennsylvania

Event narrative

Snow quickly entered Northwest Pennsylvania during the late afternoon hours on the 24th. By the evening hours, snowfall rates increased to one inch per hour as more organized snow bands moved through the region on the northwest side of the low pressure system. After midnight on the morning of the 25th, snow transitioned to a multi-banded lake effect snow event with variable snow amounts across Northwest Pennsylvania on Christmas Day. By evening, conditions changed to allow for a dominant single lake effect snow band to develop to the lee of Lake Erie and significant snowfall accumulations, in excess of 2 inches per hour, developed closer to the lakeshore in Erie County with lesser amounts through the southern portion of the county. Lake effect snow began to fizzle early on the 26th and snow activity dwindled through the rest of the day with most of the accumulating snowfall ending later in the morning. Impacts across the region were limited to mostly travel impacts as the holiday already closed schools and businesses. Interstate 90 had brief closures due to snow and accidents, especially during the evening of the 25th. The maximum snowfall for this hybrid snow event in the southern portion of Erie County was in Summit Township, where a trained snow spotter recorded a total of 29.5 inches of snow by late morning on the 26th. Other selected storm totals include: 25.5 inches in Greene Township, 24 inches in Colt Station, 23.7 inches in McKean, 23 inches in Greenfield Township, 22.2 inches in Northeast Township, 19.8 inches in Millcreek Township, 16.8 inches in Edinboro, 10 inches in Corry, and 9 inches in Union City.

Wider weather episode

A two-part winter storm event hit Northwest Pennsylvania for Christmas 2020. Low pressure developed over the southeastern United States on Christmas Eve and moved up the spine of the Appalachian Mountains through the day. Moderate to heavy snow entered Northwest Pennsylvania late afternoon on Christmas Eve with the northwest side of this system. By evening, snow became more organized across the area and snow bands, producing one to one inch per hour snowfall rates, raked across the region just after midnight. Snowfall amounts across the region were between 6 and 9 inches of snow with the first part of the event. The low quickly departed out of the region after midnight on Christmas morning, but very cold air infiltrated the region. This air mass, along with a wide open, warmer Lake Erie, allowed for lake effect snow to develop across the traditional snow belt region of Northwest Pennsylvania. While initial snow was a more multi-banded setup during the day on Christmas, eventually snow became more organized into a single dominant band across Lake Erie by the evening hours. This band set up along the lakeshore portions of Erie County and several hours of 2 to 3 inch per hour snowfall rates were observed with this lake effect snow band. Nearby Interstates 90 and 86 were heavily impacted by snow on Christmas night. Snow became more unorganized during the early morning hours of the 26th and conditions improved for most areas after daybreak. With the lake effect portion of the event, the lakeshore areas of Erie County received an additional 10 to 24 inches of snow. There was a more even distribution of snow further south in Erie County into Crawford County with new snow accumulations of 5 to 12 inches with the lake effect event . The highest total snowfall measurement for the event in Pennsylvania was 30.5 inches by a trained snow spotter in Lake City in northern Erie County. Erie International Airport received a total of 18.7 inches of snow for the event. Impacts during the event were very limited to travel, as schools and businesses were closed due to the holiday. There were no known injuries or fatalities in Northwest Pennsylvania due to the winter storm.

Source: NOAA Storm Events Database, event_id 935196. Narrative written by the NWS forecast office that issued the report.