A long duration winter storm event occurred from roughly January 26 through January 28th as a powerful storm system affected much of the western United States. Periods of snow, heavy at times (especially across the mountains) occurred. Event total snow amounts of 5 to 10 inches across area valleys and the Plains were common with upwards of 2 feet of snow falling across portions of area mountains. The snow was followed by a seasonably strong arctic outbreak. Southwest Montana felt the brunt of the arctic airmass with several locations experiencing wind chill values of -40 F or colder (isolated areas having wind chill values of -50 F to -60 F), with isolated locations reaching actual air temperatures of -40 F.

Extreme Cold/Wind Chill in NORTHWEST BEAVERHEAD COUNTY, MONTANA
From 30-JAN-23 00:00:00 to 30-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

COOP observer located near Wisdom reported a minimum air temperature of -46 F. Images of a reliable digital sensor about 2 miles west of Wisdom measured an air temperature of -52 F at 7:30 AM MST. A sensor about 6 miles southwest of Wisdom recorded an air temperature of -40 F.

Heavy Snow in GALLATIN VALLEY, MONTANA
From 27-JAN-23 00:00:00 to 28-JAN-23 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Observer at MSU Bozeman campus reported an event total snow amount of 8.7 inches. Additionally, a CoCoRaHS observer on the southeast side of Bozeman reported 9.3 inches. A trained spotter 5 miles east of Gallatin Gateway reported an event total of 15 inches. Locations around Belgrade reported 6 to 7 inches for an event snow total.

Heavy Snow in BIG BELT, BRIDGER AND CASTLE MOUNTAINS, MONTANA
From 27-JAN-23 02:00:00 to 28-JAN-23 06:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

SNOTEL automated equipment estimated 12 inches of new snow over a 24-hour period at Boulder Mountain. Station elevation was 7,889 feet.

Heavy Snow in MADISON RIVER VALLEY, MONTANA
From 26-JAN-23 23:00:00 to 28-JAN-23 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Norris Madison Observer, located about 4 miles east of McAllister, reported an event total snow amount of 16 inches. 12 inches fell over a 24 hour period ending around sunrise on Jan 28th.

Heavy Snow in LITTLE BELT AND HIGHWOOD MOUNTAINS, MONTANA
From 26-JAN-23 13:00:00 to 28-JAN-23 06:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter located about 12 miles northeast of Neihart reported an event total snow amount of 30 inches. Their elevation was approximately 6,500 feet. Additionally, SNOTEL automated equipment at Onion Park estimated 11 inches of new snow over 30 hours. 6 inches of snow fell during the first 24 hours. Station elevation was 7,640 feet. SNOTEL automated equipment at Daisy Peak estimated 7 inches of new snow. Station elevation was 7,600 feet. SNOTEL automated equipment at Spur Park estimated 6 inches of new snow over 24 hours. Station elevation was 8,097 feet. A member of the public 7 miles south-southeast of Neihart reported 12 inches of snow.

Heavy Snow in SNOWY AND JUDITH MOUNTAINS, MONTANA
From 26-JAN-23 15:00:00 to 28-JAN-23 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

SNOTEL automated equipment at Crystal Lake estimated 12 inches of new snow for an event total. Station elevation was 6,213 feet. Elsewhere, a Co-Op observer located about 11 miles south of Lewistown reported an event snow total of 8 inches.

Winter Weather in FERGUS COUNTY BELOW 4500FT, MONTANA
From 26-JAN-23 22:00:00 to 28-JAN-23 12:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Spotters and Co-Op observers reported 5 to 7 inches for event total snowfall across the lower elevations of Fergus County.

Winter Weather in JUDITH BASIN COUNTY AND JUDITH GAP, MONTANA
From 26-JAN-23 22:00:00 to 28-JAN-23 17:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Co-Op observer in Stanford reported an event snow total of 4 inches.

Winter Storm in GALLATIN AND MADISON COUNTY MOUNTAINS AND CENTENNIAL MOUNTAINS, MONTANA
From 26-JAN-23 20:00:00 to 27-JAN-23 21:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

State police handled 45 slide-offs/jackknifed/stranded vehicle incidents. 12 multi-vehicle incidents. 2 incidents with jackknifed semi. Majority of these incidents occurred on US 191. SNOTEL automated equipment at Divide estimated 10 inches of snow over a 24-hour period. Elevation of the station was 7,810 feet. SNOTEL automated equipment at Black Bear estimated 12 inches of snow over a 24-hour period. Elevation of the station was 8,144 feet. SNOTEL automated equipment at Short Creek estimated 9 inches of snow over a 24-hour period. Elevation of the station was 6,993. SNOTEL automated equipment at Lick Creek estimated 11 inches of snow over a 24-hour period. Elevation of station was 6,701 feet.

Extreme Cold/Wind Chill in GALLATIN AND MADISON COUNTY MOUNTAINS AND CENTENNIAL MOUNTAINS, MONTANA
From 29-JAN-23 00:00:00 to 29-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Minimum wind chill values measured by various official equipment included: -48 F about 1 mile north of Raynolds Pass, -42 F about 6 miles NNW of Lakeview, -46 F about 7 miles SSW of Big Sky, -40 F about 4 miles west of Big Sky, -44 F about 6 miles WSW of Big Sky, -41 F about 4 miles southeast of Virginia City, and -42 F about 16 miles southeast of Gallatin Gateway.

Extreme Cold/Wind Chill in ELKHORN AND BOULDER MOUNTAINS, MONTANA
From 29-JAN-23 00:00:00 to 29-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A minimum wind chill of -61 F was measured by an official sensor located about 11 miles southwest of Basin.

Extreme Cold/Wind Chill in MEAGHER COUNTY VALLEYS, MONTANA
From 29-JAN-23 00:00:00 to 29-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A minimum wind chill of -42 F was measured by an official sensor located about 2 miles WNW of White Sulphur Springs as well as by a an official sensor located in Martinsdale.

Heavy Snow in CASCADE COUNTY BELOW 5000FT, MONTANA
From 26-JAN-23 17:00:00 to 28-JAN-23 12:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

COOP observer at Hill Top Colony reported a 24-hour snow total of 6 inches. A spotter located about 7 miles south-southeast of Ulm reported an event snow total of 8 inches over approximately a 36-hour time frame.

Heavy Snow in UPPER BLACKFOOT AND MACDONALD PASS, MONTANA
From 27-JAN-23 09:00:00 to 28-JAN-23 12:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter located about 11 miles west of Helena reported an event total snowfall between 6 and 8 inches, but stated drifting and blowing of snow made a precise measurement difficult.

Winter Storm in NORTHWEST BEAVERHEAD COUNTY, MONTANA
From 26-JAN-23 20:00:00 to 28-JAN-23 11:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter located about 4 miles north of Polaris reported an event total snow amount of 16 inches. SNOTEL automated equipment at Darkhorse Lake estimated 15 inches of snow over a 36-hour period. 8 inches of snow fell over the first 12-hours. Elevation of the station was 8,484 feet.

Winter Storm in ELKHORN AND BOULDER MOUNTAINS, MONTANA
From 27-JAN-23 00:00:00 to 28-JAN-23 02:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

SNOTEL automated equipment at Rocker Peak estimated 10 inches of snow over a 24-hour period. 6 inches of snow fell over an 8-hour period. Elevation of the station was 7,857 feet. SNOTEL automated equipment at Tizer Basin estimated 8 inches of snow over a 24-hour period. Elevation of the station was 6,922 feet. SNOTEL automated equipment at Frohner Meadow estimated 12 inches of snow over a 24-hour period. Elevation of the station was 6,627 feet.

Extreme Cold/Wind Chill in GALLATIN AND MADISON COUNTY MOUNTAINS AND CENTENNIAL MOUNTAINS, MONTANA
From 30-JAN-23 00:00:00 to 30-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A minimum air temperature of -40 F was measured by an official sensor about 8 miles north of West Yellowstone.

Extreme Cold/Wind Chill in SOUTHERN HIGH PLAINS, MONTANA
From 29-JAN-23 00:00:00 to 29-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Military AWOS site K1FM, located about 8 miles NNE of Augusta, measured a minimum wind chill value of -40 F.

Extreme Cold/Wind Chill in SNOWY AND JUDITH MOUNTAINS, MONTANA
From 29-JAN-23 00:00:00 to 29-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

Judith Peak RAWS site, located about 7 miles ESE of Hilger, recorded a minimum wind chill value of -43 F.

Heavy Snow in GATES OF THE MOUNTAINS, MONTANA
From 26-JAN-23 13:00:00 to 28-JAN-23 12:00:00 (MST-7)
Reported by: COOP Observer

COOP observer located near Adel reported an event total snow amount of 13 inches.

Heavy Snow in EAST GLACIER PARK REGION, MONTANA
From 27-JAN-23 04:00:00 to 28-JAN-23 07:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Badger Pass SNOTEL automated equipment estimated 11 inches of new snow over 22 hours. SNOTEL site at Many Glacier estimated 7 inches of new snow for a 24 hour total.

Heavy Snow in SOUTHERN ROCKY MOUNTAIN FRONT, MONTANA
From 27-JAN-23 06:00:00 to 28-JAN-23 07:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

Dupuyer Creek SNOTEL automated equipment estimated 15 inches of new snow over 22 hours.

Heavy Snow in SOUTHERN HIGH PLAINS, MONTANA
From 27-JAN-23 17:00:00 to 28-JAN-23 09:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter located about 17 miles WSW of Bynum reported 11 inches of new snow over about a 16 hour period.

Heavy Snow in GATES OF THE MOUNTAINS, MONTANA
From 26-JAN-23 20:00:00 to 28-JAN-23 18:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

NWS employee located about 6 miles northeast of Craig reported an event total snow amount of 10.1 inches.

Extreme Cold/Wind Chill in RUBY MOUNTAINS AND SOUTHERN BEAVERHEAD MOUNTAINS, MONTANA
From 30-JAN-23 00:00:00 to 30-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A minimum air temperature of -40 F was measured by an official sensor about 7 miles NNW of Monida.

Extreme Cold/Wind Chill in RUBY MOUNTAINS AND SOUTHERN BEAVERHEAD MOUNTAINS, MONTANA
From 29-JAN-23 00:00:00 to 29-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A minimum wind chill of -46 F was measured by an official sensor in Monida.

Extreme Cold/Wind Chill in LITTLE BELT AND HIGHWOOD MOUNTAINS, MONTANA
From 29-JAN-23 00:00:00 to 29-JAN-23 10:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: RAWS

A minimum wind chill of -44 F was measured by the Judith Basin RAWS site, located about 12 miles NNE of Checkerboard.