Lawinenlagebericht

Flathead Range & Glacier NP

Flathead Avalanche Center
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Lawinengefahr

Fri
Hochgebirge
4 · Gross
Waldgrenze
4 · Gross
Unterhalb
3 · Erheblich
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Kernpunkte

We’ve extended the Avalanche Warning to Saturday morning. Exceptionally warm temperatures and rain are causing very dangerous avalanche conditions. Slab avalanches can break thousands of feet wide and be large enough to snap mature trees. Large wet loose avalanches will occur on all aspects and elevations. Avoid traveling on or underneath any steep slope. 

Lawinenprobleme

  • Loose Wet

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Very Likely
    Größe
    1–2

    Yesterday’s rain and consecutive days of above-freezing temperatures have put the wet loose avalanche problem into full swing. Last week's nice, cold powder snow is now saturated with water and has either avalanched or is about to avalanche. 

    The signs that this problem exists will be avalanches. Plain and simple. We are beyond the days of looking for rollerballs and waiting for it to happen. Wet loose avalanches can run through forested slopes, so allow the slope angle to guide your route. See the adjacent photo for an example of a wet loose slide running in not-so-obvious avalanche terrain. 

    A photo from 2023 when debris from a wet avalanche reached the marion lake trail. This terrain does not look like your typical avalanche path. 

    Photo: Flathead Avalanche Center

  • Persistent Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Likely
    Größe
    2.5–4

    Today is not a day to travel anywhere exposed to overhead hazards. A natural avalanche failing at upper elevations will travel a long way as it gouges out and entrains substantial amounts of wet debris.

    “Backcountry bombs” are in full force. Cornice falls and wet loose avalanches will be dropping loads onto slopes with an untrustworthy weak layer. These buried weak layers are being stressed as heat and water change the snowpack.

    Wet Slab: Once liquid water reaches buried weak layers, it will weaken the bonds between grains, causing the weak layer to collapse. The result will be a very destructive and unsurvivable avalanche. The travel advice for dealing with a wet slab problem or a persistent slab problem is the same: avoid avalanche terrain.

    (3/17/2026)

    Impressive slab avalanche that propogated widely and ran 2500 vertical feet. 

    Photo: Michael Reavis

Avalanche Discussion

We are extending the Avalanche Warning to Saturday morning. Unseasonably warm temperatures and forecasted rain will prolong HIGH avalanche danger. Travel on, below, or near avalanche terrain right now is a very risky endeavor. Avalanches may run long distances and entrain a substantial amount of wet debris. A triggered avalanche will be destructive.

As prolonged warm and wet weather continues, we expect a mess of different kinds of avalanches. We will see persistent slabs, wet slabs, cornice falls, and wet loose avalanches. I’m sure of that. I won’t be surprised at all if we even have some glide avalanches wipe out the season's snowpack. Hopefully, a break in the cloud cover today will allow us to assess the type and extent of avalanche activity so far.  

The amount of natural avalanche activity may vary greatly within forecast zones due to recent rainfall. Precipitation, in the form of rain, has favored the northern Whitefish Range and central Glacier National Park. We anticipate that a wet slab avalanche cycle is underway in those regions. Areas not favored by rainfall may soon follow.

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