Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
View on map

Avalanche danger

Tue
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
Open full map
Out of date — this forecast expired 2 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Be alert for dense slabs of drifted snow. These will be more common and larger near the summits of peaks and on the leeward (easterly) side of the Flathead and Swan Ranges. You've found a potential slab when you've found hard snow that cracks under your weight or the weight of your snowmachine.

Avalanche problems

  • Wind Slabs

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

    Be alert for pockets of dense, drifted snow at upper elevations. These should be confined to slopes most prone to collecting wind-blown snow. Examples include the tops of chutes and couloirs, as well as steep slopes below cornices and downwind of saddles. 

    Most of these slabs formed late last week and are slowly stabilizing. Most reports note short, shallow cracks confined to ridgelines. One report from the northern Whitefish Range noted a small, remotely triggered slab that failed on weak facets. 

    Small pockets of drifted snow can have outsized consequences in confined terrain, like chutes and couloirs, and above cliffs and gullies. 

    (1/12/2025) Able to trigger this 50’ wide wind slab just below Hornet Wx Station. Slab was about 20 cm thick and failed on a layer of NSF.

Avalanche Discussion

We've dropped the Persistent Slab avalanche problem that's lingered the past two weeks or so. While riders have been getting into high-consequences terrain likely to harbor the problem, they've reported no incidents or signs of instability. Large column tests aren't producing propagation on either the 12/7 facets/ buried surface hoar, or facets above the mid-December crust. Snowpack models are showing the 12/7 layer to be problematic in only 3 of 51 modeled profiles for the region. That's a lot of evidence from multiple sources that says avalanche breaking in old snow are unlikely. 

That leaves triggering dense slabs of drifted snow the primary avalanche concern today. Based on recent observations, those are generally small and isolated below about 7000 feet. You're most likely to encounter this hazard above that elevation, in exposed terrain near the summits of peaks in the Whitefish and Swan Ranges, along the crest of the Flathead Range, and in central Glacier Park. Keep an eye out for this hazard; no need to ruin a midwinter day high in the mountains with a surprise slide.

Two other avalanche hazards are worth keeping in mind, though they're not widespread enough to list as problems currently:

  • Dry, loose snow slides: Several reports have noted natural or triggered sluffs running on the snow surface. As the surface snow facets, these may become more common in steep terrain.
  • Glide avalanches: People have noticed glide cracks near Essex, in the Mission Mountains, on the Swan Front, and in the southern Whitefish Range. Managing your exposure to these is straightforward - don't travel below them. 

Descriptions of riding conditions have ranged from "crust battle" to "swish." In some locations, stout crusts exist but have been buried by recent snowfall. Conditions are highly variable from drainage to drainage, so choose wisely. 

Regions covered