Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Recent avalanches and loud, whumpfing collapses yesterday should make you second guess entering consequential terrain today. Steer around wind drifted features on the leeward side of exposed ridgelines and cross-loaded gullies. Warm temperatures may cause the surface snow to become wet and avalanche. Hedge your bets by selecting concave slopes with clean runouts. Limit your exposure to large avalanche paths.  

Avalanche problems

  • Persistent Slabs

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

    Weak layers buried 1 to 2 feet below the surface continue to show signs that they are untrustworthy. On Sunday, a large avalanche was reported in the northern Whitefish Range. Other reports of loud audible collapses happened in the Flathead Range. Triggering a slide 1 to 2 feet thick is more of a concern in areas where a slab was stiffened, or thickened by the wind. Warm temperatures today will help settle recent snow into a slab, making the problem more widespread. Steer away from convex slopes and slopes that terminate in a stand of trees.

    (2/6/2022)

    A large avalanche in Clarence Creek, in the northern Whitefish Range. Possibly triggered by a snowmobile.

    Photo: Seth Carbonari

  • Wind Slabs

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

    Winds are cranking at speeds up to 50 mph at the highest ridgelines. Blowing snow was observed Sunday at upper elevations in the Flathead Range and near the Continental Divide. Watch out for thin wind slabs below ridgelines and in cross-loaded gullies. A thin wind slab may step down to a buried weak layer, triggering a larger, more dangerous avalanche.

    (2/4/2022)

    Wind slab triggered on a test slope in southern Glacier National Park. 

    Photo: Ted Steiner

  • Loose Wet

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

    Freezing levels may climb to 7000 feet today, making loose wet avalanches a concern on all aspects. The snow on shaded aspects may get moist and wet thanks to warm air and intermittent greenhousing from cloud cover. This will be more of a problem on slopes sheltered from south and west winds. If you feel the snow become moist and see rollerballs, avoid steep slopes and don't dawdle below large avalanche paths.

    (2/6/2022)

    Roller balls on a steep mid-elevations slope. These indicate a person on the same slope might be able to trigger a small, wet loose avalanche.

    Photo: Cam Johnson

Avalanche Discussion

On most days in the past week, we have received reports of audible collapses and propagating snowpit tests. These are failing on buried layers of surface hoar or faceted crusts (observation). On Friday, there was an incident in the southern Whitefish Range where the third skier on a slope triggered an avalanche that broke on the surface hoar; they were pushed into a tree and had to be freed by their partners. On Sunday, another report of a suspected snowmobile-triggered avalanche occurred in the northern Whitefish Range. Both of these avalanches were large enough to bury a person. 

Unfortunately, this problem isn’t going to go away any time soon. Strong winds will continue to stiffen slabs on all aspects and freezing levels reaching up to 7000 feet will help settle snow into slabs on all aspects. If you want to avoid the possibility of triggering an avalanche failing 1 to 2 feet thick altogether, stick to slopes less than 35 degrees. If you decide to step out into avalanche-prone terrain, choose terrain with clean runouts and have a partner spotting you in a safe zone.

The biggest change the snowpack will see today is the warm temperatures. Weather models are showing bands of clouds and moderate to strong winds which can cause some slopes to become unstable, and other slopes to remain stable. If you see cloud cover roll in and don’t feel the wind, expect a greenhousing effect, which can quickly wet the snow surface and cause it to slide. If cloud cover does not roll in and you feel the warm sun, be wary of sunny aspects that aren’t getting clipped by south and westerly winds. Many of today's avalanche problems are on the cusp of being dangerous. A subtle change in cloud cover or wind will change surface conditions quickly.

Regions covered