Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Out of date — this forecast expired 9 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

The likelihood of triggering an avalanche up to a foot thick will rise today as snow begins to pile up. Heavy snowfall rates, shooting cracks, and/or blowing snow are signs to move to lower-angle slopes.

The avalanche danger will rise to CONSIDERABLE if snowfall totals exceed 8 inches. 

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    New snow may form fresh slabs as the day progresses. Expect stiffer and thicker slabs just downwind of ridges and chutes. These slabs may rest above a weak layer of surface hoar that was buried earlier this week, increasing the potential for remote triggering.

    Adjust your travel techniques as quickly as conditions change. Snowfall rates exceeding 1 inch an hour are a sign of rapid change, which should direct you to slopes with lower angles. Shooting cracks are signs you've found the ingredients for an avalanche. Test the sensitivity of new and recent snow by stomping on small and inconsequential test slopes with a spotter. 

    (12/18/2024)

    This is a photograph of an avalanche taken last season. Soft slab avalanche up to a foot thick, like this one, will be the flavor of avalanches we expect to see by the end of the day. 

    Photo: Flathead Avalanche Center

Avalanche Discussion

An active weather pattern is expected to persist for the foreseeable future, starting today. Mentally prepare for rising avalanche danger throughout the day and weekend. 

Today, expect .2 to .7 inches of precipitation by nightfall. This can translate to roughly 3 to 8 inches of new snow. The Swan Range will likely see the high end of those snow totals. The Flathead Range should see around 3 to 5 inches, and the Whitefish Range will probably pick up the lowest end of the totals. Wind speeds today will barely tickle thresholds optimal for transporting snow into fresh slabs along exposed ridgelines at upper elevations. 

Progressively dial back your terrain selection as snow begins to pile up. Move to lower-angle slopes if you see signs of shooting cracks or trigger avalanches on small slopes. I expect this kind of behavior in the Swan and Flathead Ranges, but I don't expect enough snow to change the avalanche danger in the Whitefish Range. 

Guy and Josh traveled around the resort boundary yesterday before today's opening and found a generally stable snowpack. Observations from all three ranges this weekend found no signs of unstable snow underfoot. Observers did photograph surface hoar and near-surface facets before Monday's snow. There is a fair amount of uncertainty due to the lack of observations since that layer was buried. This layer should be 3 to 12 inches below the surface and will appear as a grey stripe. Observations are incredibly valuable to us, especially early in the season. 

Regions covered