Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

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Out of date — this forecast expired last year.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

Highlights

Though unlikely, you can still trigger a large avalanche on buried weak layers where the snowpack is not capped by a hard crust. Shifting winds may form drifts on slopes facing all directions. Steer away from etched snow surfaces or dune-shaped features along ridges and in open bowls. 

Avalanche problems

  • Wind Slabs

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

    Shifting winds have deposited recent snow on both typical and atypical leeward slopes. In many areas drifts are resting on firm crusts and may be more reactive.  Expect slabs to be thicker and more widespread in areas favored by recent snow and wind, like along the Continental Divide. 

    Look for signs of wind-affected snow along exposed ridges, cross-loaded gullies or bowls, and downwind from prominent terrain features. Rippled snow surfaces and dune-shaped features are visual cues of wind-affected snow. Cracking around your feet or machine are signs of unstable snow that should direct you to less steep or more sheltered terrain. Slabs 8+ inches thick will be difficult to manage.  Recognize that slab thickness can vary significantly across a slope. 

    (3/5/2025)

    Scalloped surfaces and dune-shaped features are obvious signs of recent wind.  Choose slopes that are less steep or more sheltered from the wind to avoid triggering an avalanche in wind-drifted snow. 

    Photo: Lydia Fahrenkrug

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–2.5

    February's Atmospheric River and warming produced widespread avalanches on buried weak layers. While it is unlikely, you can still trigger a large avalanche that breaks 2 to 3 feet deep on steep, shaded slopes where weak layers were not wiped out by recent avalanches or capped by a thick and supportable crust.  Keep in mind that slopes harboring the softest riding conditions are exactly where you can find this problem. Likely trigger points include convex roll-overs or slopes peppered with rocks. 

    Weak layers may not give obvious signs of instability before avalanching. Dig below the surface to look for layers of buried surface hoar, facets, and faceted crusts before traveling on or under steep slopes. Sudden collapses or propagation in column tests are prompts to dial back your terrain selection to lower-angled or less complex slopes. 

    (3/2/2025)

    Widely propagating avalanche off the ridge south of Mount Liebig. You are most likely to trigger a large avalanche on shaded alpine slopes where weak layers were not wiped out by recent avalanches or capped by a stout melt-freeze crust. Likely trigger points include convex roll-overs or slopes peppered with rocks. 

    Photo: Paul Fotter

Avalanche Discussion

In a sing-song voice: “Not quite winter, nor quite spring. Somewhere in the in-between.”

Winter-like conditions remain on shaded slopes above roughly 5000’:

  • Buried weak layers could still be intact on slopes that didn’t produce large avalanches in the late February AR and thawing.
  • Slopes facing NW-N-NE-E have only a thin surface crust, making it possible for a human or their machine to trigger large avalanche on these layers.
  • Snowpack tests continue to produce unstable results.
  • Some modest snowfall and winds may have formed small windslabs in favored locations.

If uncertainty is the affliction, a shovel is the remedy. If you don't feel a stout crust below your feet or machine, dig down to look for (and test) buried weak layers. Unstable test results suggest you either seek out simple terrain or settle for firmer riding conditions. 

Our (slight) reprieve from aggressive thawing will continue today. However, near-freezing temperatures and sunshine will make it possible to find some Loose Wet instabilities on solar slopes.

  •  Sluffs should be limited to the recent snow above the melt-freeze crust from last weekend. While the crust will prevent entrainment and limit the size of any avalanche, it could cause slides to travel further than you expect.
  • Today we are lacking the usual southwest breeze which can cool slopes facing south and west. Loose wet activity could develop quickly on steep and rocky mid-elevation slopes that receive direct sunlight.
  • Fresh rollerballs and pinwheels are signs that wet snow is ready and willing to slide. Recognize that even small slides can have severe consequences if you are raked through exposed rocks and trees, pushed over a cliff, or deposited in a creek bed.

Many glide cracks have been reported across the advisory and several failed during last weeks warming. While glide avalanches are unlikely today, don’t press your luck by parking, playing, lunching, etc. below these hazards.

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