Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
View on map

Avalanche danger

Wed
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

New thin slabs of drifted snow may form throughout the day. Slabs should be harmless in size unless you get caught and pushed into consequential terrain features. Steer around areas that are actively getting loaded by wind at upper elevations. Give yourself a margin for error by riding one at a time and selecting slopes with smooth runouts. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    1–1.5

    Observations from all three ranges describe 5 to 8 inches of recent snow sitting on a melt-freeze crust. Wind speeds will slowly increase this afternoon, drifting this snow into fresh slabs.  Look for blowing snow for a visual clue for terrain to steer around. Choose windward slopes, or tuck in beneath slabs of drifted snow for relatively safer riding. If you don't see evidence of drifting snow in the area you travel, watch for loose dry sluffing in very steep terrain. These should be easy to manage and small in size. 

    (1/15/2023)

    Natural avalanche that failed in the last week. 

    Photo: Cam

Avalanche Discussion

Observations from yesterday (Monday) generally point to relatively safe avalanche conditions. New snow accumulations appear to average roughly 5 to 8 inches. One rider found this new snow to sluff easily in steep terrain in the Flathead Range, and another person found this new snow slabby and breaking above the crust in the Whitefish Range. Mark and Sarah found the recent melt-freeze crust up to 6700 feet in the Swan Range. Temperatures dropped below freezing at all elevations, reducing the chance of wet snow avalanches.

Today winds are forecast to increase and average between 10 to 15 mph at upper ridgelines. This increase in winds looks to be later in the afternoon. I suspect southwesterly winds will drift snow into small, thin slabs below ridgelines and gullies. These slabs should be relatively harmless in size and easy to manage by tucking in below areas of active drifting. Select terrain sheltered from the wind or choose windward aspects. 

Slabs of drifted snow are more of a concern in the Swan Range. A weak layer of surface hoar was buried on January 9th. On January 11th, a rider remotely triggered a large slab avalanche at 6200 feet. On January 15th, my partner and I remotely triggered two slab avalanches above 6500 feet. These failed roughly a foot thick. Yesterday, Mark and Sarah searched up and down on the west side of the Swan Range and could not find this layer reactive in snowpit tests. So far, this proves the distribution may be “spotty,” or harder to find. Right now, our primary travel advice for the Swan Range is to steer towards aspects that face south and west to reduce your chances of triggering a slab avalanche. Choose lower angled slopes if you decide to ride where winds drifted snow into thicker slabs. 

With recent rain and warm temperatures, we suspect this layer of surface hoar more of a problem at upper elevations, but added middle elevations for a wider margin. So far this problem is only found in the Swan Range. 

Regions covered