Bollettino valanghe

Flathead Range & Glacier NP

Flathead Avalanche Center
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Pericolo valanghe

Sun
Alta quota
1 · Debole
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

Today's wintry mix may develop wet avalanches where light rain falls on dry snow. As snowfall develops, thin slabs of wind-drifted snow could form at upper elevations this afternoon. The danger will rise overnight and through Sunday, with strong winds and moderate snowfall. 

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    In locations where today's precipitation falls as rain, wet snow avalanches may develop. These will be confined to the area above the freezing rain but below the snow line. Slopes harboring cold, dry snow will be most susceptible. This will be less of a problem in areas open to the sun where a surface crust developed this week.

    Early signs of instability will be snow falling from tree branches and pinwheels or rollerballs developing. While traveling through the rain zone, limit your exposure to overhead steep slopes and time spent above terrain traps. Default to lower-angle terrain if you find a moist snow surface.

     

    (12/6/2024)

    The popular Skook Face is just northeast of the WMR ski area boundary. The blue ellipse highlights steeper terrain riddled with wet loose debris. The right side of the image shows multiple ski tracks on lower-angle terrain with virtually no wet debris visible. 

    Photo: Mark Dundas

Avalanche Discussion

Light Pacific moisture arrives today after nearly a week of high pressure. Expect a possible messy wintry mix as the relatively warm moisture interacts with cold air pooled near the valley floor. Today's forecast is unclear, but freezing rain may extend from the valley floor to somewhere near the top of the cold air. Perhaps 4000-5000 feet. Above that will be a band of rain extending up to where it is cold enough for snow to develop. 

Today's avalanche concern in the Flathead, GNP, and Swan Range should be confined to the rainfall band, where dry snow will warm for the first time. Wet slides will also be a concern in the Whitefish Range; however, this area is favored for snowfall and may develop thin slabs of wind-drifted snow by sunset. We have added a wind slab problem to this zone and bumped the hazard to MODERATE at upper elevations. There is a slight chance of this problem developing in other zones. 

The real action starts tonight as a cold front drops temperatures and the main moisture surge arrives. Nearly an inch of water may fall by Sunday morning, with up to a foot of snow in favored locations and windy conditions. Fresh slabs will form on widespread surface hoar or faceted crusts, increasing the sensitivity to triggering and expanding the distance slides propagate. 

Did you hear about the app? You can now access our region's forecasts, observations, and weather data directly from the Avy App (IOS; Android). Many features are accessible offline, so you can win debates about the avalanche problems right in the backcountry or submit an obs while driving home. 

Registration is open for this season's avalanche courses. Get some learning done!  There's an Avalanche Awareness class on Wednesday, December 11th, at 6:00 pm at the Stonefly Lounge in Coram.

Regioni coperte