Avalanche forecast

Swan Range

Flathead Avalanche Center
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Avalanche danger

Sun
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
1 · Low
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Highlights

Today's avalanche hazard is directly related to how much snow falls throughout the day. Stormy weather overnight formed widespread slabs in the fresh snow. As the new snow accumulates, these will become easier for a rider to trigger. The danger will be greater in areas of wind-blown snow at upper elevations. 

Avalanche problems

  • Storm Slabs

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

    The Swan Range was favored for overnight snowfall, which led to a developing storm slab problem. Today's stormy weather will allow fresh slabs to thicken and increase their distribution throughout the day. They will form on various surfaces, including recent low-density snow, scoured hard windboard, crusts, or hard and soft slabs of varying ages. 

    Fresh slabs will be most dangerous in locations where the wind drifts the snow into thicker slabs near ridgelines, below saddles, and on cross-loaded terrain features. 

    Slabs can be identified by a denser snow surface, which may crack beneath your or your machine's weight, indicating you have found a sensitive slab. Choose lower-angle terrain to limit being surprised.

    (12/27/2024)

    An airblast (4#s of explosives on pole) triggered this hard slab avalanche on a steep, convex, northeasterly, upper elevation slope. 

    Photo: David Kerner

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    The weak layer formed in early December is now buried 2-3+ feet deep. There may be another problematic weak layer near a crust closer to the surface, which had propagating results on Friday.  This weekend's storm cycle will add weight to buried weak layers, possibly leading to natural or triggered slides. These will be more likely in areas favored by snowfall or wind-loading.

    Most avalanche activity on the early December buried weak layer has been generally limited to north and east-facing slopes.  These slopes will be getting tested the most with today's wind-drifted snow.

    For a safer experience, choose lower-angle terrain or stick to a south or southwest aspect where the weak layer is not as well developed. 

    (12/24/2024)

    Recent natural avalanches on the lee side of the Flathead range show the lingering hazard of triggering large avalanches that break deep in the snowpack 

    Photo: Michael Reavis

Avalanche Discussion

After a series of underproducing storms, hopefully, the current storm that arrived Friday afternoon will produce as forecast. As of 0400, Noisy Basin in the Swan Range has been favored with 0.9" of SWE and 6" of snow. Most mountain stations report 2-5" overnight, with several more inches expected today. This snow accumulates on several inches of snow that have fallen over the past few days.

We have increased the avalanche danger rating to reflect new and forecasted snow totals. If today's snowfall totals fall short of expectations, we may not reach Level 3 or CONSIDERABLE danger in the Whitefish Range, Flathead Range, and Glacier Park. If the storm overproduces, we may have a higher avalanche danger at mid-elevations than expected. Either way, approach today with a mindset of finding new snow avalanche problems developing throughout the day.

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Events and Education:

Want to start your New Year on the right foot? Sign up for a Partner Rescue Clinic for motorized Riders on January 4. Check out our calendar for other upcoming events. 

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