Heavy Snow and Winter Weather in Montana, December 1 to 4, 2023

Name: Heavy Snow and Winter Weather in Montana, December 1 to 4, 2023
Start: 2023-12-01T07:00
End: 2023-12-04T08:00
Location: Montana

December 1 to 4, 2023 · NWS MSO · 3 events in 3 counties and zones

A northwest flow event set up across the Northern Rockies with a series of disturbances that moved in. This brought periods of heavy snow to area mountains and light to moderate snow for many valleys.

Where it happened

Every event with a place to put it; 3 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: 1
Injuries: 3
Property damage: $130,000
Crop damage: None recorded
Events: 3

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 MSO wrote it up.

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 Missoula, MT wrote its last area forecast discussion before the first event at Nov 30, 1:51 PM MST, 17 hours 9 minutes earlier.

Area forecast discussion, Nov 30, 1:51 PM MST, 17 hours 9 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

2 winter weather, 1 heavy snow. Local standard time, as filed.

Winter Weather, Flathead/Mission Valleys

When: December 1, 7:00 AM MST to December 2, 6:00 PM MST
Where: Flathead/Mission Valleys forecast zone
Deaths: 0 direct, 1 indirect
Injuries: 0 direct, 3 indirect
Property damage: $80,000
Reported by: Newspaper
Coordinates: 47.872, -114.424 (the zone’s center; the record gives no point)

Light snow fell across the area with amounts generally in the one to two inch range. Roads were snow covered and slick, likely contributing to a fatal crash that occurred around 0700 MST near Rollins. A school bus, with two occupants, collided with two passenger trucks on northbound Highway-93, leading to a fatality of one of the passenger truck drivers.

Heavy Snow, Bitterroot / Sapphire Mountains

When: December 1, 2:00 PM MST to December 4, 8:00 AM MST
Where: Bitterroot / Sapphire Mountains forecast zone
Reported by: SNOTEL
Coordinates: 46.508, -113.828 (the zone’s center; the record gives no point)

Heavy snow fell for locations like Lolo Pass and Lost Trail Pass. Lost Trail Pass received 21 inches of snowfall, as reported by the ski resort. Lolo Pass also received 21 inches of snowfall, as recorded by the SNOTEL.

Winter Weather, Lower Clark Fork Region

When: December 1, 3:48 PM MST to December 2, 4:00 PM MST
Where: Lower Clark Fork Region forecast zone
Property damage: $50,000
Reported by: Department of Highways
Coordinates: 47.286, -114.685 (the zone’s center; the record gives no point)

Moderate to heavy snowfall occurred, leading to snow covered roads at Lookout Pass. A number of vehicle crashes were reported, while chains were required over the pass for periods of time. Traffic cameras also showed periods of greatly reduced visibility with falling snow.

The people who died

As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.

Event	Date	Age	Sex	Where	Kind
Winter Weather, Flathead/Mission Valleys	2023-12-01	54	Male	Vehicle/Towed Trailer	Indirect

What these are

Winter Weather: Snow, sleet or freezing rain below warning levels that still caused disruption, damage or casualties.
Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.

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

The same day elsewhere

Every storm in Montana in 2023 Every state in 2023 This day in weather history Warnings in Montana, December 2023

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 2026-10-01. Each event’s entry at NCEI: 1147241, 1147243, 1147242.