Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Fri
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
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Highlights

The window for safe travel has widened as cooler weather has diminished wet snow avalanche hazards. It remains prudent to ride early and exit early, and to pass quickly under cornices, glide cracks, and steep, open slopes receiving sustained sun. The hazard may bump back up Friday as partly sunny skies and warmer temperatures return.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    2–3.5

    A lingering hazard of large to very large natural wet slab avalanches remains today's primary concern. The debris from these slides can run the full length of avalanche paths, particularly where it's channeled in gullies. Don't get swallowed by one of these monsters. Stay out from under steep, sunny start zones that are receiving or have received sustained sun.   

    (3/29/2022)

    A very large natural wet slab avalanche that released near the summit of Stanton Mountain left this 30-foot deep pile of debris near Lake McDonald. For scale, the yellow arrow points at a person on the debris.

    Photo: Jenny Cloutier

  • Cornices

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

    The week-long spell of warm, sunny weather weakened large cornices, creating the potential for large sections to break off and send shed-sized chunks of very hard debris tumbling downhill. That hazard lingers under and near isolated ridges as the snowpack cools. Avoid being a bowling pin by staying out from under overhanging cornices. If you're traveling on a ridge, keep in mind that cornices can break surprisingly far back.

    (3/30/2022) null Photo: Cam Johnson

    Steep slopes below corniced ridges can be bowling lanes for chunks of hard debris.

Avalanche Discussion

A cold front that passed through the region around sunset brought a few rain and snow showers and gusty winds to the forecast region. After mostly cloudy skies overnight, freezing levels this morning are around 4500 feet. Above that elevation, weather stations have recorded 6 to 36 hours of freezing temperatures. Gusty winds have also helped keep the snow surface cool or refrozen. Mostly cloudy skies, more gusty winds, and cool temperatures today should also inhibit melting at the snow surface.

Wet snow avalanches and cornice falls are unlikely in these conditions. Cam found meltwater several feet below the snow surface Wednesday, and the cooler temps likely haven't penetrated that deep in the snowpack yet. I also doubt that cornice roots have refrozen yet. So there's a lingering hazard of wet slab and cornice fall avalanches on isolated slopes. It'd be prudent to avoid steep, sunny bowls that aren't shaded by higher peaks or ridges. And avalanche paths below large, overhanging cornices, which are bowling lanes for large chunks of very hard debris. 

Today the window for safe travel will be much wider than it has been for days. And travel conditions are easier, with the snowpack consolidating and supportable melt-freeze crusts at mid and upper elevations. Cam found good corn riding about mid-morning Wednesday, though these deteriorated by late morning. Where the crusts don't soften, an trace to a few inches of new snow may make it easier to hold an edge, though sidehilling may remain tough. Continue to plan your routes to avoid being under large slopes receiving sustained sun late in the day, glide cracks, and looming cornices. 

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