In the wake of a cold frontal passage that also produced severe thunderstorms the day prior, ample northwesterly flow off of Lake Erie allowed for lake effect snow showers across much of northern and western Pennsylvania during the morning and afternoon hours of March 17, 2026. A narrow corridor of surface-based instability provided a narrow window for snow squall potential during the afternoon…
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CTP wrote it up.
In the wake of a cold frontal passage that also produced severe thunderstorms the day prior, ample northwesterly flow off of Lake Erie allowed for lake effect snow showers across much of northern and western Pennsylvania during the morning and afternoon hours of March 17, 2026. A narrow corridor of surface-based instability provided a narrow window for snow squall potential during the afternoon hours along Interstate 80 in Clearfield County. Snow squalls were observed on Interstate 80 near Penfield on two separate occasions with no incidents reported. Snow showers began to decrease in coverage during the evening hours, eventually tapering off after sunset.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS State College, PA wrote its last area forecast discussion before the first event at Mar 16, 2:14 PM EST, 23 hours 16 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
2 winter weather. Local standard time, as filed.
SNOW SQUALL. The PennDOT RWIS station at exit 111 on Interstate 80 recorded a visibility of less than a quarter of a mile in heavy snow as a snow squall moved through. The road surface temperature dropped from 35.8 degrees to 29.5 degrees in 30 minutes.
SNOW SQUALL. The PennDOT RWIS station at exit 111 on Interstate 80 recorded a visibility of less than a quarter of a mile in heavy snow as a snow squall moved through. The road surface temperature dropped from 38.1 degrees to 28.2 degrees in 25 minutes.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2026Every state in 2026This day in weather historyWarnings in Pennsylvania, March 2026
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-10-01. Each event’s entry at NCEI: 1317634, 1317635.