For the second time during the 2013/2014 winter season, a strong arctic cold front plowed south and west across western Montana. The initial push of arctic air undercut moist Pacific air causing heavy snow, blowing snow and poor visibility. This arctic outbreak was very similar to those that occurred in early December of 1972 and also in 1956.

Heavy Snow in FLATHEAD/MISSION VALLEYS, MONTANA
From 02-DEC-13 16:55:00 to 02-DEC-13 21:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Ronan Airport AWOS sensor reported northerly winds to 31 mph with the arctic front passage. Heavy snow, blowing snow reducing visibility, and slick conditions on US-93 from Ronan to Polson were reported by MT DOT at 6:50 pm MST. At 8:22 pm MST, MT DOT reported heavy snow with snow-covered roads from MT-200 west of Dixon to Ravalli and on Highway-212, 4 miles north of Dixon to Moise. Total snowfall ranged from 2 to 4 inches.

Winter Weather in MISSOULA / BITTERROOT VALLEYS, MONTANA
From 02-DEC-13 20:25:00 to 03-DEC-13 03:53:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: NWS Employee

The arctic front passed through Missoula a little after 8 pm MST and brought 0.5 of snow, blowing snow with a few northerly wind gusts over 30 mph through 10 pm MST on Dec. 2. Visibilities fell down close to zero briefly with the combination of falling snow and blowing snow.  A person from the public reported strong winds, blowing snow and whiteout conditions on US-93 between Missoula and Lolo around 11:36 pm MST on Dec. 2. Half an inch of snow fell at the Missoula Airport, 1  to 2 fell in Lolo and 3 fell in the Grant Creek area 4 miles north-northwest of Missoula.

Winter Storm in KOOTENAI/CABINET REGION, MONTANA
From 02-DEC-13 12:00:00 to 02-DEC-13 16:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: 911 Call Center

A person from the public in Olney reported heavy snow with blowing snow creating whiteout conditions on US-93 near mile-marker 145. Although snow totals ranged between 2 to 3 inches across the area, this all fell within 2 to 3 hours ahead and with the arctic cold front passage. It was this sudden change with falling temperatures from above freezing to the teens, that caused roads to become very slick with several automobile slide-offs reported by the Flathead County dispatch between Olney and Whitefish. The Eureka Airport AWOS reported visibilities less than or equal to one-quarter mile from 11:56 am to 1:46 pm MST while the City of Eureka webcam indicated falling snow.

Winter Storm in BUTTE / BLACKFOOT REGION, MONTANA
From 02-DEC-13 11:00:00 to 02-DEC-13 15:50:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

An arctic cold front pushed through MacDonald Pass in the morning and brought periods of heavy snow and blowing snow reducing visibilities to near whiteout at times. The Deer Lodge AWOS reported visibilities less than one-quarter mile for 1.4 hours, while northerly winds gusting to 37 mph occurred as the arctic cold front passed through. A weather spotter at 6,200 ft., 2 miles southwest of Newcomb,  measured 5.5 inches of heavy snow, 5 hours ending at 3:50 pm MST. They also reported that 6 to 10 inches of snow fell across the higher elevations.

Winter Weather in POTOMAC / SEELEY LAKE REGION, MONTANA
From 02-DEC-13 14:00:00 to 02-DEC-13 21:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained weather spotter, located 1.5 miles south of Condon, reported 1.5 of snow. Both the North Fork Jocko SNOTEL at 6,330 ft. and Kraft Creek SNOTEL at 4,750 ft. measured 2 of total snowfall. Falling temperatures from the middle 30s to upper teens in the Condon area combined with the snowfall brought slick conditions on MT-83.

Heavy Snow in WEST GLACIER REGION, MONTANA
From 02-DEC-13 05:00:00 to 02-DEC-13 16:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

A railroad weather sensor at 4,520 ft., located 6.4 miles southwest of Marias Pass, measured 2 per hour snowfall rates between 6 and 8 am MST on Dec. 2. It also depicted a distinct wind shift with falling temperatures between 9 and 10 am MST, associated with an arctic cold front passage. It measured a total storm snowfall of 5.5 inches. A person from the public located in Essex, estimated that 12 inches of total snow fell during this event. They also reported that 6 inches of that fell as heavy snow with and behind the arctic front passage near 9:30 am MST. At 1 pm MST, the MT DOT reported that chains were required on towing units on US-2 from Essex to 7 miles west of Marias Pass.

Heavy Snow in BITTERROOT / SAPPHIRE MOUNTAINS, MONTANA
From 01-DEC-13 02:00:00 to 03-DEC-13 04:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: SNOTEL

The Saddle Mountain SNOTEL at 7,900 ft. located about 1.7 miles west-southwest of Lost Trail Pass on US-93 received 27 inches of total storm snow with 3.50 inches of snow water equivalent. An intense, 4 hour period of heavy snow amounting to 9 inches fell between 4 and 8 pm MST on Dec. 1. At 1:40 pm MST Dec. 1, the Montana DOT reported that chains were required on towing units for Lost Trail Pass. The heaviest snowfall, according to the SNOTEL, appeared to have stopped by 2 pm MST on Dec. 2, but periods of light to moderate snow continued through the morning hours of Dec. 3.

Heavy Snow in LOWER CLARK FORK REGION, MONTANA
From 02-DEC-13 17:00:00 to 03-DEC-13 05:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

The Montana DOT reported heavy snow with snow-covered roads on MT-200 from Trout Creek to west of Plains at 6:18 pm MST on Dec. 2. By 7 pm MST, they reported heavy snow on MT-28 junction with MT-200 to 10 miles north. The MT DOT also reported heavy snow on US-93 at Evaro Hill. Rain had fallen earlier in the day on the 2nd and when the arctic front went through by 6 pm MST at Trout Creek, snow froze quickly to the road making for very slick conditions.  On Dec. 3, the MT DOT indicated that from 5:23 am to 7:11 am MST, there were severe driving conditions on MT-200 from Trout Creek to just west of Plains due to snow-pack and black ice.

Blizzard in FLATHEAD/MISSION VALLEYS, MONTANA
From 02-DEC-13 13:00:00 to 02-DEC-13 16:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter located 2 miles west-southwest of Columbia Falls reported visibilities near zero from at least 1 to 3 pm MST due to blowing snow. During this time-frame the Glacier Park International Airport ASOS sensor reported frequent gusts between 32 and 38 mph. Based on this, wind speeds could have been reaching near 50 mph towards the Bad Rock Canyon on US-2. The Flathead County 911 dispatch reported that 15 vehicle slide-offs and accidents occurred during a time span of less than two hours inside and outside of the Kalispell city limits, some of which contained injuries. The Flathead Beacon tweeted at 3:31 pm MST, Terrible driving conditions currently-please drive with caution. Even though snowfall amounts were low and near 2 inches, the sudden change from dry roads to near whiteout conditions with dropping temperatures caused high impact to the Flathead Valley.