Lake-Effect Snow and Winter Weather in Pennsylvania, December 4 to 6, 2024

Name: Lake-Effect Snow and Winter Weather in Pennsylvania, December 4 to 6, 2024
Start: 2024-12-04T17:30
End: 2024-12-06T13:00
Location: Pennsylvania

December 4 to 6, 2024 · NWS CTP · 8 events in 8 counties and zones

Where it happened

Every event with a place to put it; 8 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 2
Property damage: None recorded
Crop damage: None recorded
Events: 8

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.

What happened

The episode as NWS CTP wrote it up.

Snowfall began during the early morning hours of December 5, 2024 across the northern tier with warm air advection within an enhanced low level jet ahead of a cold frontal passage beginning to overspread snowfall across central Pennsylvania. Enhanced frontogenetic forcing and instability in the lower levels allowed for some snow squalls to form across the Laurel Highlands and Middle Susquehanna Valley, with some snow bands continuing into the Lower Susquehanna during the morning commute. Northwesterly flow behind the cold frontal passage allowed for lingering lake effect snow showers across portions of northwestern Pennsylvania, with heavy lake effect snow continuing through December 6th. A snow squall along Interstate 80 in southern Clinton County caused a multi-vehicle accident with 10 tractor trailers and 3 to 4 passenger vehicles, closing the roadway for multiple hours and injuring two motorists.

What forecasters said that day

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 Dec 3, 6:35 PM EST, 22 hours 55 minutes earlier.

Area forecast discussion, Dec 3, 6:35 PM EST, 22 hours 55 minutes before

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The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

5 lake-effect snow, 3 winter weather. Local standard time, as filed.

Winter Weather, Southern Clinton

When: December 4, 5:30 PM EST to 6:00 PM EST
Where: Southern Clinton forecast zone
Injuries: 0 direct, 2 indirect
Reported by: Mesonet
Coordinates: 41.234, -77.638 (the zone’s center; the record gives no point)

SNOW SQUALL. RWIS data indicated a rapid drop in visibility to a quarter of a mile with roadways becoming snow covered quickly in a snow squall. Air and surface temperatures were already below freezing before the snow squall, but data indicated a 4 degree drop in surface temperatures during the squall. This squall resulted in a multi-vehicle incident on Interstate 80 involving 10 tractor trailers and 3 to 4 passenger vehicles, closing the roadway for multiple hours.

Winter Weather, Southern Centre

When: December 5, 1:55 AM EST to 2:05 AM EST
Where: Southern Centre forecast zone
Reported by: Department of Highways
Coordinates: 40.919, -77.820 (the zone’s center; the record gives no point)

SNOW SQUALL. An RWIS site on Interstate 99 near Port Matilda reported a 2 to 3 degree drop in surface temperatures along with visibility dropping to one quarter mile within a snow squall. Webcams in the surrounding area also showed accumulating snow on roadways in the squall for a period of 5 to 10 minutes.

Lake-Effect Snow, Warren

When: December 5, 4:30 AM EST to December 6, 1:00 PM EST
Where: Warren forecast zone
Reported by: Trained Spotter
Coordinates: 41.815, -79.274 (the zone’s center; the record gives no point)

Snow began during the early afternoon of December 4th, and continued into the evening. This snow was generally light, with snowfall totals under 2 inches reported across Warren County. After a break in the snowfall, lake effect snow bands began to move in from the northwest. This snow continued through early afternoon on Friday, December 5th. While most of the county saw 4 to 6 inches of snow from these lake effect bands, 8 inches of snow fell in the city of Warren and 9 inches fell in Tidioute.

Lake-Effect Snow, McKean

When: December 5, 4:30 AM EST to December 6, 1:00 PM EST
Where: McKean forecast zone
Reported by: COOP Observer
Coordinates: 41.808, -78.569 (the zone’s center; the record gives no point)

Snow began during the early afternoon of December 4th, and continued into the evening. This snow was generally light, with snowfall totals under 2 inches reported across McKean County. Lake effect snow began in the early morning on Thursday, December 5th and continued through the afternoon of Friday, December 6th. Much of McKean County saw 3 to 5 inches of snow from these lake effect bands, but 14 inches of snow was reported in Kane. There was also a report of 8 inches of snow near the town of Cyclone.

Lake-Effect Snow, Elk

When: December 5, 4:30 AM EST to December 6, 1:00 PM EST
Where: Elk forecast zone
Reported by: Public
Coordinates: 41.425, -78.649 (the zone’s center; the record gives no point)

Snow began during the early afternoon of December 4th, and continued into the evening. This snow was generally light, with snowfall totals under 2 inches reported across Elk County. After a break in the snowfall overnight, lake effect snow began to fall during the early morning hours of Thursday, December 5th. The snow continued to fall periodically through the early afternoon on Friday, December 6th. Snow totals across much of Elk County ranged from 2 to 4 inches, though 6.5 inches of snow was reported near the town of Force.

Lake-Effect Snow, Potter

When: December 5, 4:30 AM EST to December 6, 1:00 PM EST
Where: Potter forecast zone
Reported by: CoCoRaHS
Coordinates: 41.745, -77.896 (the zone’s center; the record gives no point)

Snow began during the early afternoon of December 4th, and continued into the evening. This snow was generally light, with snowfall totals under 2 inches reported across Potter County. Lake effect snow bands impacted the county at times from the early morning on Thursday, December 4th through the early afternoon on Friday December 5th. Snowfall totals across much of the county ranged from 2 to 4 inches, though 6 inches of snow was reported near the town of Roulette.

Lake-Effect Snow, Cameron

When: December 5, 4:30 AM EST to December 6, 1:00 PM EST
Where: Cameron forecast zone
Reported by: COOP Observer
Coordinates: 41.437, -78.204 (the zone’s center; the record gives no point)

Snow began during the early afternoon of December 4th, and continued into the evening. This snow was generally light, with snowfall totals under 2 inches reported across Cameron County. Lake effect snow bands impacted portions of the county at times from the early morning hours on Thursday, December 5th through the early afternoon on Friday, December 6th. Much of the county saw snowfall totals of up to 5 inches, but 6 inches of snow was reported near Stevenson Dam.

Winter Weather, Northern Centre

When: December 5, 5:05 AM EST to 5:15 AM EST
Where: Northern Centre forecast zone
Reported by: Department of Highways
Coordinates: 40.919, -77.820 (the zone’s center; the record gives no point)

SNOW SQUALL. An RWIS site on Interstate 80 near Snowshoe reported a drop to a quarter of a mile with heavy snow in the squall allowing for accumulating snow covering roadways.

What these are

Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.
Lake-Effect Snow: Heavy snow in bands downwind of a large lake as cold air crosses warmer water.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Pennsylvania in 2024 Every state in 2024 This day in weather history Warnings in Pennsylvania, December 2024

Sources

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: 1222057, 1221001, 1224212, 1224214, 1224218, 1224235, 1224237, 1221002.