A deepening low pressure system associated with a strong, closed-off 500mb low moved from the central Gulf Coast to central PA Sunday and Sunday night, taking an unusual track across the spine of the Appalachians. This placed Northwest Pennsylvania in the area of snowfall on the northwest side of the storm Sunday evening into Monday with snow only slowly departing the Snowbelt on Monday as lake enhancement contributed to continued heavy snowfall there well into the day.
The combination of the storm's size, track, intensity, and amount of moisture led to a heavy snow event for all of Northwest Pennsylvania. This area was sandwiched between warmer and more humid mid-level air drawn up east of the storm and colder, drier air being pulled in from the west. This tightening temperature gradient aloft (known as frontogenesis), along with the region being on the nose of a very strong easterly flow aloft, drawing in unusual amounts of moisture drawn from the Atlantic, and an atmosphere that was less stable than usual contributed to banded, very heavy snowfall across much of Northwest Pennsylvania for several hours late Sunday evening through early Monday morning. Snowfall rates of 1 to 2 inches per hour were common in this banded snow, and continued in the deformation snow that was enhanced by Lake Erie in the Snowbelt into Monday afternoon. These prolonged heavy rates made roads nearly impassable in many areas come Monday morning. The snow was initially wet Sunday evening, with some brief mixed precipitation occurring in parts of interior Northwest Pennsylvania. The snow became higher ratio, lighter snow into Monday morning, with winds turning gusty into Monday and causing blowing and drifting. Where lake enhanced snow continued well into Monday in the Snowbelt, totals of over 2 feet occurred.
Impacts from this event were significant for the Martin Luther King Jr. holiday. While schools and several businesses were closed for the holiday, many businesses scheduled to be open during the holiday either remained closed or were delayed opening. Roads across the region were impassable for hours due to heavy snow. Many accidents occurred with stranded vehicles remaining across area highways for days. The highest snowfall total from this event in Northwest Pennsylvania was 25 inches in Erie. Other selected totals across the area include: 23.9 inches in Millcreek Township, 23 inches in Summit Township, 22.7 inches in Greene Township, 22 inches in Greenfield Township, 21.9 inches in Cherry Hill, 20 inches in Girard and Spring Township, 19.8 inches in Harborcreek, 18.9 inches in Meadville, 18.8 inches in Lake City, 18 inches in Corry, 17.8 inches in Springboro, 17.5 inches in Edinboro, 16.7 inches in Cochranton, 16.2 inches at Erie International Airport, 16.1 inches in North East Township, 15.9 inches in Conneaut Lake, 14.5 inches in Atlantic, 13.5 inches in Union City, 10.7 inches in Titusville, and 10.5 inches northwest of Jamestown.

Winter Storm in NORTHERN ERIE, PENNSYLVANIA
From 16-JAN-22 17:00:00 to 17-JAN-22 17:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow began during the evening hours of January 16, quickly increasing in intensity during the overnight hours. Many locations woke up to a foot or more of snow on the morning of January 17, causing impassable roads across the area. Lake enhanced snowfall continued across the area during the morning and afternoon hours of January 17 before fading away to just flurries and blowing snow during evening hours. Total snowfall for the event in northern Erie County ranged from 16 to 25 inches of snow. The maximum snowfall for this event was in the city of Erie, where a snow spotter recorded 25 inches of snow. Other measured snowfall amounts for this event included: 24.7 inches in Millcreek Township, 20 inches in Girard, 19.8 inches in Harborcreek, 18.8 inches in Lake City, and 16.2 inches at Erie International Airport.

Winter Storm in SOUTHERN ERIE, PENNSYLVANIA
From 16-JAN-22 17:00:00 to 17-JAN-22 17:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow began during the evening hours of January 16, quickly increasing in intensity during the overnight hours. Many locations woke up to a foot or more of snow on the morning of January 17, causing impassable roads across the area. Lake enhanced snowfall continued across the area during the morning and afternoon hours of January 17 before fading away to just flurries and blowing snow during evening hours. Total snowfall for the event in southern Erie County ranged from 13 to 23 inches of snow. The maximum snowfall for this event was in Summit Township, where a snow spotter recorded 23 inches of snow. Other measured snowfall amounts for this event included: 22.7 inches in Greene Township, 22 inches in Greenfield Township, 21.9 inches in Cherry Hill, 18 inches in Corry, 17.5 inches northwest of Edinboro, 16.1 inches in North East Township, and 13.5 inches in Union City.

Winter Storm in CRAWFORD, PENNSYLVANIA
From 16-JAN-22 17:00:00 to 17-JAN-22 17:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Snow began during the evening hours of January 16, quickly increasing in intensity during the overnight hours. Many locations woke up to a foot or more of snow on the morning of January 17, causing impassable roads across the area. Lake enhanced snowfall continued across the area during the morning and afternoon hours of January 17 before fading away to just flurries and blowing snow during evening hours. Total snowfall for the event in Crawford County ranged from 10 to 20 inches of snow. The maximum snowfall for this event was in Spring Township, where a snow spotter recorded 20 inches of snow. Other measured snowfall amounts for this event included: 18.9 inches in Meadville, 17.8 inches in Springboro, 16.7 inches in Cochranton, 15.9 inches in Conneaut Lake, 14.5 inches in Atlantic, 10.7 inches in Titusville, and 10.5 inches northwest of Jamestown. Lesser amounts in the southern portions of Crawford County were attributed to a brief period of mixed precipitation.