Blizzard and Winter Storm in Montana, November 21 to 23, 2010

Name: Blizzard and Winter Storm in Montana, November 21 to 23, 2010
Start: 2010-11-21T19:00
End: 2010-11-23T08:00
Location: Montana

November 21 to 23, 2010 · NWS MSO · 8 events in 7 counties and zones

Very cold arctic air moving out of Canada combined with a moist pacific storm system. This produced blizzard conditions across much of western Montana, along with very cold wind chill temperatures.

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: 0
Property damage: $15,000
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 MSO wrote it up.

Very cold arctic air moving out of Canada combined with a moist pacific storm system. This produced blizzard conditions across much of western Montana, along with very cold wind chill temperatures.

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 21, 2:59 PM MST, 4 hours 1 minute earlier.

Area forecast discussion, Nov 21, 2:59 PM MST, 4 hours 1 minute 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 heavy snow, 2 extreme cold/wind chill, 2 winter storm, 1 blizzard, 1 cold/wind chill. Local standard time, as filed.

Heavy Snow, Flathead/Mission Valleys

When: November 21, 7:00 PM MST to November 22, 8:00 AM MST
Where: Flathead/Mission Valleys forecast zone
Reported by: Trained Spotter
Coordinates: 47.872, -114.424 (the zone’s center; the record gives no point)

Measured 7 inches of snow 4 miles ne of Ronan.

Extreme Cold/Wind Chill, Butte / Blackfoot Region

When: November 22, 4:00 AM MST to 2:00 PM MST
Where: Butte / Blackfoot Region forecast zone
Reported by: Department of Highways
Coordinates: 46.306, -113.025 (the zone’s center; the record gives no point)

MDOT weather observation reported wind chill readings of 25 below to 30 below zero from 1 pm to 6 pm at Powell Mt. ASOS at Bert Mooney airport in Butte reported a wind chill temperature of 28 below zero.

Heavy Snow, Bitterroot / Sapphire Mountains

When: November 22, 4:00 AM MST to November 23, 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)

Chains were required over Lolo Pass. Lolo pass Snotel reported 7 inches of snow over 24 hours.

Extreme Cold/Wind Chill, West Glacier Region

When: November 22, 4:00 AM MST to 9:00 AM MST
Where: West Glacier Region forecast zone
Reported by: Department of Highways
Coordinates: 47.971, -114.069 (the zone’s center; the record gives no point)

MDOT equipment at Essex Mt reported a wind chill of 21 below zero.

Winter Storm, West Glacier Region

When: November 22, 4:00 AM MST to 9:00 AM MST
Where: West Glacier Region forecast zone
Reported by: Department of Highways
Coordinates: 47.971, -114.069 (the zone’s center; the record gives no point)

Estimated 7 inches of snow in Condon Mt.

Winter Storm, Missoula / Bitterroot Valleys

When: November 22, 5:00 AM MST to 10:00 AM MST
Where: Missoula / Bitterroot Valleys forecast zone
Property damage: $15,000
Reported by: Law Enforcement
Coordinates: 46.560, -114.023 (the zone’s center; the record gives no point)

Local blizzard conditions were reported through Hellgate canyon. Highway patrol reported several high impact accidents.

Blizzard, Lower Clark Fork Region

When: November 22, 9:30 PM MST to November 23, 4:30 AM MST
Where: Lower Clark Fork Region forecast zone
Reported by: Department of Highways
Coordinates: 47.286, -114.685 (the zone’s center; the record gives no point)

DOT reported blizzard conditions with heavy snow, 9 inches reported at Evaro and 8 inches reported at Ninemile.

Cold/Wind Chill, Potomac / Seeley Lake Region

When: November 22, 10:00 PM MST to November 23, 6:00 AM MST
Where: Potomac / Seeley Lake Region forecast zone
Reported by: Department of Highways
Coordinates: 46.986, -113.597 (the zone’s center; the record gives no point)

Wind chill of 24 below zero reported at Clearwater and DOT reported whiteout conditions.

What these are

Heavy Snow: Snowfall reaching the local warning threshold without the other hazards of a winter storm.
Extreme Cold/Wind Chill: Temperatures or wind chills at or below the local warning criteria, or cold that caused deaths.
Winter Storm: A storm that brought snow, sleet or freezing rain at warning levels, usually over several hours or days.
Blizzard: Sustained winds or frequent gusts of 35 mph or more with falling or blowing snow that cuts visibility below a quarter mile for three hours or longer.
Cold/Wind Chill: Cold or wind chill below warning criteria that caused deaths, injuries or damage.

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

The same day elsewhere

Every storm in Montana in 2010 Every state in 2010 This day in weather history Warnings in Montana, November 2010

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: 268009, 268917, 268918, 268921, 268922, 268920, 268924, 268923.