Bollettino valanghe

Flathead Range & Glacier NP

Flathead Avalanche Center
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Pericolo valanghe

Wed
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 8 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Dangerous avalanche conditions are expected to develop throughout the day. 4 to 8 inches of new snow and strong winds will create new slabs sensitive to the weight of a person or machine. Opt for more conservative terrain as snow accumulates, and avoid areas where you see active wind loading. IF snow totals reach the higher end, or exceed forecasted totals, plan to manage a more widespread storm slab problem.

An Avalanche WATCH is in effect. Expect very dangerous avalanche conditions to develop in the next 24 to 48 hours. Natural and human-triggered avalanches are likely.

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1.5–2.5

    Strong winds will transport new snow into hard slabs on the leeward side of ridges, gullies, and saddles. Slabs will become thicker and more dangerous as snow totals accumulate throughout the day. Expect to manage a more widespread Storm Slab problem if precipitation totals exceed 8 inches of new snow. New snow is landing on a firm crust, making it so a triggered avalanche could run far distances.

    Let precipitation totals guide your travel today. Seek more conservative terrain if more than 6 inches of new snow has accumulated. Cracking around your skis or board indicates you’ve found a slab. Use small, inconsequential test slopes to assess new snow sensitivity, and avoid areas with active wind loading.

    (12/7/2025)

    This image is of cross-loaded gullies. The arrows indicate the wind-direction. Note the scoured rock and snowy gullies. I'd expect to find hard slabs of wind-drifted snow in gullies today. 

    Photo: Michael Reavis

Avalanche Discussion

We have issued an Avalanche Watch with the expectation of reaching HIGH avalanche danger by tomorrow morning. IF the precipitation forecast verifies, new snow and strong winds will create very dangerous avalanche conditions.

Today’s avalanche forecast relies on the precipitation forecast. Precipitation favors the Flathead Range, Whitefish Range, and Glacier National Park (4 to 8 inches), with another 5 to 10 inches overnight. The Swan Range will pick up 1 to 3 inches today and 5 to 10 inches overnight. Precipitation should start around noon, becoming heavy at times. Wind speeds are well above thresholds for transporting new snow into stiff slabs. Snow densities will increase throughout the day, making the storm snow “upside-down,” and potentially more sensitive to the weight of a person or machine.  

Because the avalanche danger rests on the shoulders of the precipitation forecast, if snow totals don’t reach forecast amounts throughout the day, expect the avalanche danger to be one step lower in each forecast zone. If we get skunked on snow, or if you head out first thing this morning, the only problem you should have to manage is isolated wind slabs in the upper reaches of the forecast zone.

Regioni coperte