Warm advection ahead of low pressure pushing up the Ohio Valley produced a 4 to 6 hour period of moderate to heavy snow across the southern Allegheny Mountains of Pennsylvania during the morning of January 9, 2024. As much as 12 inches of snowfall was observed atop the Allegheny Front in eastern Somerset and eastern Cambria counties, with localized snowfall rates of 2-3 inches per hour.
Every event with a place to put it; 4 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.
Warm advection ahead of low pressure pushing up the Ohio Valley produced a 4 to 6 hour period of moderate to heavy snow across the southern Allegheny Mountains of Pennsylvania during the morning of January 9, 2024. As much as 12 inches of snowfall was observed atop the Allegheny Front in eastern Somerset and eastern Cambria counties, with localized snowfall rates of 2-3 inches per hour. This system also produced 1.5 to 2.5 inches of rain across the Cumberland and Susquehanna valleys, resulting in localized flooding.
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 Jan 9, 1:06 AM EST, 2 hours 54 minutes earlier.
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</html>The national radar mosaic for the moment the first event began.
5 flood, 3 heavy snow, 1 winter weather. Local standard time, as filed.
A winter storm produced 7 to 9 inches of snowfall across Somerset County, with localized amounts on the higher terrain ranging from 10 to 12 inches, as snow began in the morning hours of January 9, 2024 and continued into the afternoon.
A winter storm produced 7 to 9 inches of snowfall across higher elevations of Cambria County as snow fell throughout the morning hours of January 9, 2024.
A winter storm produced 6 to 7 inches of snowfall across higher elevations of Blair County as snow began in the morning hours of January 9, 2024 and continued into the afternoon.
Snowy conditions led to a jack-knifed tractor trailer on the PA Turnpike (I-76), leading to a several-hour lane restriction on the eastbound lanes.
Heavy rain and snowmelt led to flooding on Leafmore Road to the southeast of Saint Thomas, closing the road.
Heavy rain and snowmelt led to flooding on Petersburg Road near Boiling Springs, closing the roadway.
Heavy rain and snowmelt led to flooding near Conowingo Creek in East Drumore Township, with water rising up to the doors on a midsized sedan.
Heavy rain and snowmelt led to flooding along Pequea Creek in West Lampeter Township.
Heavy rain and snowmelt led to the Conestoga River flooding a stretch of North Conestoga Drive to the east of the city of Lancaster.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2024Every state in 2024This day in weather historyWarnings in Pennsylvania, January 2024
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 2026-09-30. Each event’s entry at NCEI: 1148616, 1148618, 1148617, 1148874, 1152181, 1152184, 1152185, 1152189, 1152192.