Boletín de aludes

Flathead Range & Glacier NP

Flathead Avalanche Center
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Peligro de aludes

Thu
Alta montaña
3 · Notable
Límite del bosque
2 · Moderado
Bajo el límite
1 · Débil
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Desactualizado: este boletín caducó 5 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

At upper elevations, dangerous avalanche conditions may develop today. Avoid slabs of drifted snow large enough to bury and injure you by sticking to terrain sheltered from the wind. Shooting cracks and cracking around your skis or machine are signs to stick to terrain with slope angles less than roughly 35 degrees.

Problemas de aludes

  • Wind Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Likely
    Tamaño
    1–2

    As you climb higher in elevation, strong winds out of the southwest may drift new snow into firm slabs up to two feet thick. Slabs will form on the leeward side of ridges and cross-load gullies further downslope. Signs of drifting snow and pillowy-looking surfaces are your cues to seek wind-sheltered terrain. Terrain sheltered from the wind will be safer and more enjoyable to ride in.

    (12/5/2021)

    Winds from different directions have top-loaded and cross-loaded this ridgeline.

    Photo: Dundas

Avalanche Discussion

Expect the avalanche hazard to increase throughout the day as new snow begins to pile up. Forecast snow totals today will range from 2 to 8 inches. The Swan Range will likely see the upper end of snow totals. The Flathead Range, Glacier National Park, and the Whitefish range will likely see a little less. The main driver in today’s hazard will be the strong winds out of the southwest. Winds are expected to average around 25 mph with gusts up to 50 mph. With those kind of wind speeds, expect to see slabs form further downslope and in unusual ways. Be observant and avoid locations where you see active wind loading. Freshly formed drifts may get deposited onto older wind slabs, cold powder snow, or a freezing rain crust. 

Unfortunately, there is a fair chance that the cold powdery snow from the past couple of days is now capped with a freezing rain crust. On Tuesday, we received an observation that a rain crust formed up to 5600 feetin the Mission Range. I'd expect to find it in the southern part of the forecast area. This rain crust will be a slick surface for snow to slide on. 

Digging deeper into the snowpack at upper elevations you’ll find a dense slab that overlies a series of crusts and facets. The limited observations so far are indicating that it is unlikely to trigger one of these weak layers. However, observations are limited to elevations 7400 feet and below. If you find yourself climbing above that elevation, expect to find a potentially weaker and more dangerous snowpack.

Firewall and security issues are blocking the data from the Summit weather station at the top of Whitefish Mountain Resort from appearing on various websites. We have been and will keep working on it.  

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