Bollettino valanghe

Flathead Range & Glacier NP

Flathead Avalanche Center
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Pericolo valanghe

Tue
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Enjoy the recent snow and improved coverage while remembering you can still trigger a dangerous slab in the snow deposited over the weekend. Avoid slabs of dense snow which your skis, board, or machine ride on or near the surface.  Recognizing bulls-eye data such as recent avalanches or shooting cracks will help you have a safe and fun day. Getting caught in even a small slide may have traumatic consequences due to the early-season conditions.  

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3

    There was plenty of snow and wind over the weekend, but few observations. Field reports from the Middle Fork on Saturday noted reactive cornices and the wind blowing every which way. Sunday morning the BNSF avalanche safety team noted 10+" snow in the valley floor, blowing snow above 5000 feet, and loose snow slides. Snowfall and winds decreased Sunday morning, allowing our snowpack a bit of time to strengthen, but we are not out of the woods quite yet. As you gain elevation, look for areas of deeper snow, especially on leeward sides of ridges or downwind of saddles. Suss these spots out for slab characteristics such as stiff, dense, or textured appearance. Retreat to lower-angle slopes or sheltered terrain if you note shooting cracks.

    (12/11/2021)

    Consistent snowfall and strong winds drifted snow into reactive cornices along ridgelines. 

    Photo: Kevin O.

Avalanche Discussion

The weekend storm boosted our base and has dramatically improved riding conditions and access in most parts of the forecast area above 4000 - 4500 feet. Observations were sparse over the weekend, but several field observers Sunday noted snow totals that exceeded what the nearby WMR weather station reported.  A rider in the Stryker area enjoyed 1.5 - 2 feet of new and recent snow. At the same time, Cam found 30" of new and recent snow in Kimmerly. Most valley floor locations missed out on snowfall except in John F. Stevens Canyon, where the BNSF avalanche safety team noted 10+" at the highway level.

We elevated the avalanche danger to CONSIDERABLE at mid and upper elevations to anticipate the forecasted snow totals and wind speeds. Observations Saturday from the Apgars and Middle Fork appeared to justify the elevated danger rating. However, Sunday's observations showed otherwise, with BNSF avalanche safety reporting harmless D1 sluffs from John F. Stevens Canyon. I was adjacent to WMR, participating in an on-the-hill refresher with the fine folks from the  Flathead Nordic Backcountry Patrol, and found overall good stability.  With decreased wind speeds and snowfall ending Sunday morning or afternoon, we have dropped the danger rating to MODERATE except for the upper elevations of the Flathead Range/Glacier Park, where the danger remains CONSIDERABLE. The terrain in this zone is much larger and more alpine, with generally more wind loading and larger start zones.

Preliminary Accident Report: On Saturday morning, December 11th, an avalanche fatality occurred in the Silver Basin area of Crystal Mountain Ski Resort in Washington. See the accident summary for additional details.

Regioni coperte