For the 3rd time in the 2013/2014 season, an arctic cold front clipped western Montana. Initially, Pacific moisture allowed for light to moderate snow to develop across western Montana, with many higher elevation locations receiving several inches.  Valleys saw temperatures warm into the lower 40's F with rain showers early on Dec. 18. These milder temperatures set the stage for a flash-freezing event in the Flathead Valley east to Marias Pass when an arctic air-mass moved in by the late evening of Dec. 18. As the arctic air-mass pushed westward, gusty winds to 50 mph in the canyons caused blowing snow, while areas from West Glacier to Marias Pass saw heavy snow.

Winter Storm in WEST GLACIER REGION, MONTANA
From 18-DEC-13 10:00:00 to 19-DEC-13 08:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

MT DOT estimated that 8 to 10 inches of snow fell from West Glacier to Java East, which is located about 6 miles southwest of Marias Pass. They also reported that there was blowing and drifting snow, snow-pack and ice on US-2. They also indicated that the area south of Essex to Java East was particularly nasty. The Pike Creek SNOTEL at 5,930 ft., located about 1.6 miles southeast of Marias Pass, reported 6 of total snow with 0.20 of snow water equivalent, which gives an average snow to liquid ratio of 30 to 1. The HADS sensor at Marias Pass, reported 0.29 of liquid, which could equate to around 7.1 of snow, 6 of that fell between 4:45 and 7:45 pm MST on Dec. 18. The MT DOT sensor located at milepost 179.9 in Essex, reported gusty winds near 30 mph from 4 to 7:30 pm MST on Dec. 18, which corroborates the report of nasty conditions on US-2. An automobile accident with an injury was reported near West glacier at 4:24 pm MST on Dec. 18, while roads were reported to have snow-cover with slick conditions. Blowing snow with wind gusts near 50 mph were reported near Bad Rock canyon on the evening of Dec. 18. Other snow/liquid amounts: 7.0/0.20 Flattop Mtn. SNOTEL, 7.0/0.40 Emery Creek SNOTEL(5 SSE of West Glacier) & 4.4/0.41 West Glacier COOP.

Winter Weather in BITTERROOT / SAPPHIRE MOUNTAINS, MONTANA
From 18-DEC-13 06:00:00 to 19-DEC-13 08:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

The Lost Trail ski resort reported 3 of snow while Ski Lookout reported 2 of snow during this event.

Winter Weather in FLATHEAD/MISSION VALLEYS, MONTANA
From 18-DEC-13 17:20:00 to 19-DEC-13 04:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A spotter located in Columbia Falls, reported 3 of total snowfall, flash-freezing to formerly wet road surfaces, and blowing snow with occasional strong gusts between 30 and 50 mph. They reported that visibility lowered to less than one-quarter mile at times due to blowing snow during the evening of Dec. 18. They also said that the drive from Whitefish to Columbia Falls around 11:30 pm MST on Dec. 18, was very slick due to ice, blowing and drifting snow. The arctic cold front made it through Glacier Park International Airport around 8:22 pm MST Dec. 18 and north-northeast winds were sustained between 30-33 mph with gusts up to 45 mph through 2:35 am MST Dec. 19. The airport only reported 1 of snow, and visibilities were only reduced to one-half mile between 11:24 and 11:55 pm MST Dec. 18. Five automobile crashes and 7 slide-offs were reported in the Flathead Valley on Dec. 18.

Winter Weather in BUTTE / BLACKFOOT REGION, MONTANA
From 18-DEC-13 20:50:00 to 19-DEC-13 10:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained spotter 7 miles south of Butte at 6,200 ft., reported a total storm snowfall of 3 inches that mainly fell after midnight on Dec. 19. A weather observer at the Bert Mooney Airport also reported an estimated 3 of snowfall during the event. The temperatures ranged from the single digits below zero to the teens in the Butte area through Dec. 20, which prevented the DOT to be able to mitigate the slick roads. Wind chill values ranged between 10 and 16 below zero F. from Avon to Deer Lodge from 4:30 to 10:21 am MST on Dec. 19. A trained spotter located near Georgetown Lake reported 4 of total storm snowfall.

Winter Weather in KOOTENAI/CABINET REGION, MONTANA
From 18-DEC-13 17:00:00 to 19-DEC-13 06:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

The Olney COOP reported a total storm snowfall of 5 with 0.38 of precipitation for Dec. 19. A person from the public in Olney, tweeted that road conditions were snow-covered and snow intensities were heavy at 3:50 pm MST on Dec. 18.