Montana, 2017

Extreme Cold in Montana, December 30 to 31, 2017

December 30 to 31, 2017 · NWS TFX · 8 events in 5 counties and zones

An Arctic air mass and breezy winds ahead of a warm front resulted in extreme wind chills being reached in several North-Central Montana locations on the morning of December 30th. On the evening of the 30th, the same air mass and breezy winds allowed additional extreme wind chills to be realized in a few spots as the aforementioned front settled back to the south and west as an Arctic front.

The toll

Deaths
0
Injuries
0
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 TFX wrote it up.

An Arctic air mass and breezy winds ahead of a warm front resulted in extreme wind chills being reached in several North-Central Montana locations on the morning of December 30th. On the evening of the 30th, the same air mass and breezy winds allowed additional extreme wind chills to be realized in a few spots as the aforementioned front settled back to the south and west as an Arctic front. Lastly, clearing skies and light winds accompanying an Arctic ridge of high pressure resulted in significant nocturnal cooling on New Year's Eve evening into the morning of New Year's Day, prompting a wind chill warning for portions of North-Central Montana.

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 Great Falls, MT wrote its last area forecast discussion before the first event at Dec 29, 10:30 PM MST, 4 hours 4 minutes earlier.

Area forecast discussion, Dec 29, 10:30 PM MST, 4 hours 4 minutes before
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In the hours before

Local storm report, Dec 29, 10:20 PM MST, 4 hours 14 minutes before
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Local storm report, Dec 29, 10:29 PM MST, 4 hours 5 minutes before
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Local storm report, Dec 29, 10:30 PM MST, 4 hours 4 minutes before
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Local storm report, Dec 29, 11:23 PM MST, 3 hours 11 minutes before
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Local storm report, Dec 30, 12:17 AM MST, 2 hours 17 minutes before
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Event by event

8 extreme cold/wind chill. Local standard time, as filed.

Extreme Cold/Wind Chill, Blaine

When
December 30, 2:34 AM MST
Where
Blaine forecast zone
Reported by
Department of Highways

MT DOT station near Hays reported -43F wind chill with sustained wind of 20 mph.

Extreme Cold/Wind Chill, Liberty

When
December 30, 6:01 AM MST
Where
Liberty forecast zone
Reported by
COOP Observer

COOP station 9 miles SE of Whitlash reported wind chill of -43F with sustained wind of 17 mph.

Extreme Cold/Wind Chill, Liberty

When
December 30, 10:40 AM MST
Where
Liberty forecast zone
Reported by
COOP Observer

COOP station 5 miles NNW of Chester reported wind chill of -44F with sustained wind of 21 mph.

Extreme Cold/Wind Chill, Cascade

When
December 30, 6:05 PM MST
Where
Cascade forecast zone
Reported by
Department of Highways

MT DOT station near Monarch Canyon reported -40F wind chill with sustained wind of 13 mph.

Extreme Cold/Wind Chill, Toole

When
December 31, 5:15 AM MST
Where
Toole forecast zone
Reported by
Department of Highways

MT DOT station near Sunburst recorded -58F wind chill with sustained wind of 12 mph.

Extreme Cold/Wind Chill, Eastern Glacier

When
December 31, 8:30 AM MST
Where
Eastern Glacier forecast zone
Reported by
Mesonet

Mesonet station 18 miles ENE of Babb reported wind chill of -40F with sustained wind of 12 mph.

Extreme Cold/Wind Chill, Blaine

When
December 31, 6:18 PM MST
Where
Blaine forecast zone
Reported by
RAWS

Fort Belknap RAWS reported -46F wind chill with sustained wind of 10 mph, gusting to 12 mph.

Extreme Cold/Wind Chill, Toole

When
December 31, 9:35 PM MST
Where
Toole forecast zone
Reported by
Department of Highways

Sweet Grass MT DOT station reported wind chill of -49F with sustained wind of 26 mph, gusting to 30 mph.

What these are

Extreme Cold/Wind Chill
Temperatures or wind chills at or below the local warning criteria, or cold that caused deaths.

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

The same day elsewhere

More

Every storm in Montana in 2017Every state in 2017This day in weather historyWarnings in Montana, December 2017

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: 727410, 727409, 727408, 727411, 727407, 727412, 725883, 725882.