A strong storm affected the mid-Atlantic and much of the Eastern Seaboard from January 16-17, 2022. A strong negative tilt trough over the Southeast US spurred strong cyclogenesis near the Carolina coast late on January 16. This low would proceed to quickly deepen as it moved northward that evening and night. Upper level steering patterns caused the low to take an ���inside runner��� track which kept the low center inland of the coast. A very strong easterly low level jet developed in between the strengthening low and a departing high pressure center to the north. With the center of the low tracking west of the region and an influx of marine air courtesy of the low level jet, various precipitation types occurred during this event. An Arctic air mass had been in place in advance of this system, but due to the aforementioned factors, that air mass rapidly modified on the 16th. As precipitation arrived, temperatures remained cold enough for it to begin as snow in most areas away from the coast. However, a rapid transition from snow to mixed precipitation to rain occurred in most areas within hours. Frozen precipitation held on for longer across the interior, where some higher snowfall amounts occurred. The storm departed the region by early on January 17.

Winter Weather in DELAWARE, PENNSYLVANIA
From 16-JAN-22 16:45:00 to 16-JAN-22 20:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. A trained spotter in Chadds Ford reported 2.2 inches of snow.

Winter Weather in PHILADELPHIA, PENNSYLVANIA
From 16-JAN-22 16:45:00 to 16-JAN-22 21:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. Snowfall amounts of 0.5 to 1.5 inches were observed, and the Philadelphia International Airport (KPHL) ASOS measured 0.05 inches of ice accretion.

Winter Weather in EASTERN CHESTER, PENNSYLVANIA
From 16-JAN-22 16:45:00 to 16-JAN-22 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. A report of 2.6 inches of snow was received from Malvern.

Winter Weather in WESTERN CHESTER, PENNSYLVANIA
From 16-JAN-22 16:45:00 to 16-JAN-22 22:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. A trained spotter in Elverson reported 2.9 inches of snow.

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

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. A trained spotter in Norristown reported 3.1 inches of snow, and a spotter in Willow Grove reported 0.01 inches of ice accretion.

Winter Weather in WESTERN MONTGOMERY, PENNSYLVANIA
From 16-JAN-22 17:00:00 to 16-JAN-22 22:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. A report of 2.0 inches of snow was received from near Franconia Twp. In addition, the Pottstown Limerick Airport (KPTW) ASOS reported 0.03 inches of ice accretion.

Winter Weather in LOWER BUCKS, PENNSYLVANIA
From 16-JAN-22 16:45:00 to 16-JAN-22 22:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. In Doylestown, a report of 2.5 inches of snow was received, and the Doylestown Airport (KDYL) ASOS reported 0.02 inches of ice accretion.

Winter Weather in UPPER BUCKS, PENNSYLVANIA
From 16-JAN-22 17:00:00 to 16-JAN-22 23:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Mixed precipitation fell. After a brief period of snow, some freezing rain fell before precipitation changed to all rain. A report of 2.7 inches of snow was received from Chalfont.

Winter Weather in BERKS, PENNSYLVANIA
From 16-JAN-22 16:45:00 to 17-JAN-22 01:30:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Mixed precipitation fell. After a period of snow, some freezing rain fell before precipitation changed to all rain. A trained spotter in Huffs Church report 3.5 inches of snow, and the Reading Regional Airport (KRDG) ASOS measured 0.04 inches of ice accretion.

Winter Weather in LEHIGH, PENNSYLVANIA
From 16-JAN-22 17:15:00 to 17-JAN-22 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Mixed precipitation fell. After a period of snow, some freezing rain fell before precipitation changed to all rain. Several snowfall reports of 3 to 4 inches were received. This included 3.5 inches at Lehigh Valley International Airport (KABE), where the ASOS also measured 0.21 inches of ice accretion.

Winter Weather in NORTHAMPTON, PENNSYLVANIA
From 16-JAN-22 17:15:00 to 17-JAN-22 03:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Mixed precipitation fell. After a period of snow, some freezing rain fell before precipitation changed to all rain. A trained spotter in Danielsville reported 4.3 inches of snow, with several other 3 to 4 inch reports in the county.

Winter Storm in CARBON, PENNSYLVANIA
From 16-JAN-22 17:15:00 to 17-JAN-22 11:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A prolonged period of snow and mixed precipitation fell. A report of 5.2 inches of snow was received from Lehighton. There were likely some higher amounts, as well as some areas of accumulating glaze ice.

Winter Storm in MONROE, PENNSYLVANIA
From 16-JAN-22 17:30:00 to 17-JAN-22 11:00:00 (EST-5)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A prolonged period of snow and freezing rain fell. Widespread 6 to 9 inch snowfall reports were received, with a maximum of 9.5 inches from a trained spotter in Coolbaugh Twp. Areas of accumulating glaze ice likely also occurred.