A steady stream of moisture coming in from the southwest interacted with the Arctic air sliding down from Canada, and caused heavy snow and gusty easterly winds over northwest Montana. Near whiteout conditions with snowfall rates of 1 to 2 inches per hour were observed. Some places received over 30 inches of new snow. Roads become impassable at times, particularly in the Essex to Kalispell corridor during the Monday morning commute. Previous heavy snowfall that occurred Feb. 3 and 4 compounded snow removal problems in city-centers. Airport operations had difficulty keeping runways clear during this event.

Blizzard in WEST GLACIER REGION, MONTANA
From 05-FEB-17 16:30:00 to 06-FEB-17 11:00:00 (MST-7)
Reported by: SNOTEL

US-2 over Marias Pass was closed by the Montana Department of Transportation due to impassable conditions. Severe driving conditions were issued for most highways in this portion of northwest Montana. MDT plow drivers estimated a three day snow total of 48 inches in Essex, MT. Ten foot drifts were seen in the vicinity of roads near Glacier National Park. The Flattop Mountain weather sensor in Glacier National Park reported 26 inches of snow in 24 hours. Another Department of Transportation weather sensor in Essex, MT recorded steady 30 mph winds with frequent gusts into the 40 mph range throughout the event. US-2 at milepost 153 near West Glacier was closed during the early morning hours of the 6th due to heavy snow and drifting.

Winter Storm in FLATHEAD/MISSION VALLEYS, MONTANA
From 05-FEB-17 17:00:00 to 06-FEB-17 10:00:00 (MST-7)
Reported by: Fire Department/Rescue

Glacier Park International Airport had to cancel two flights due to intense snowfall, with rates of up to 1.5 inches per hour. Winds combined with snow made it nearly impossible to de-ice planes before departure. The ASOS weather sensor at the airport recorded winds 30 mph gusting into the 40 mph range overnight. The peak wind speed was 33 mph sustained with 44 mph gusts. One airport fire crew employee was unable to get to work on time due to getting stuck in a snow drift. Ground blizzard conditions caused widespread travel impacts. A trained spotter reported glazed ice surfaces in Columbia Falls with freezing rain during the beginning of this event. The public reported very slick side roads due to freezing rain around Kalispell. This initial freezing rain made subsequent snowfall more dangerous to travelers. The US Postal Service did not deliver mail in some portions of the Flathead Valley on the 6th.

Heavy Snow in LOWER CLARK FORK REGION, MONTANA
From 05-FEB-17 00:00:00 to 06-FEB-17 08:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A local ski area reported 35 inches of snow in 36 hours. The Montana Dept. of Transportation reported several accidents along I-90 during this timeframe. Schools were closed due to heavy snow and dangerous travel conditions. The heavy snow also contributed to a power outage that caused the I-90 rest areas to close on the 6th.

Winter Storm in KOOTENAI/CABINET REGION, MONTANA
From 05-FEB-17 03:00:00 to 06-FEB-17 09:30:00 (MST-7)
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The emergency manager for Lincoln County estimated 30 to 36 inches of snow had fallen within 48 hours in Libby, MT. A Reverse 911 message went out to all citizens to warn them of this event. Schools were cancelled on Monday Feb. 6. This decision was made a day in advance of the predicted snowfall, which is extremely rare. The Eureka, MT AWOS showed visibility of less than 1 mile for over 8 hours during the peak of the event with periods of less than 0.25 mi visibility. Public reports put 2 day snow totals at 20 to 30 inches in Eureka, MT, depending on which part of town. Also there were reports of blowing and drifting snow between Kalispell and Eureka. The Fire Department in Bull Lake suffered a partial roof collapse from the heavy snow load. This trapped a type 6 fire engine within the building. The damage listed was an estimated amount. During the morning of the 5th there were reports of freezing rain on US-93.

Avalanche in WEST GLACIER REGION, MONTANA
From 06-FEB-17 00:00:00 to 06-FEB-17 01:00:00 (MST-7)
Reported by: Local Official

An avalanche covered the BNSF railway that runs parallel to US-2 near Marias Pass. Avalanche warnings and rail and road closures continued for days after the storm ended.