Winter Weather — Eastern Chester, Pennsylvania

2022-01-16 · Eastern Chester, Pennsylvania

Event narrative

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.

Wider weather episode

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.

Source: NOAA Storm Events Database, event_id 993761. Narrative written by the NWS forecast office that issued the report.