Bollettino valanghe

Flathead Range & Glacier NP

Flathead Avalanche Center
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Pericolo valanghe

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

It's possible to trigger an avalanche up to a foot thick on exposed wind-loaded terrain below upper-elevation ridges. Shooting cracks are signs to move to gentler terrain. 

A powerful storm will arrive sometime this afternoon, and avalanche danger will rise rapidly. Keep an eye on the weather and plan to be out of the mountains early.

Problemi valanghivi

  • Wind Slabs

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

    With only a few inches of recent snow and light to moderate winds, any wind slab avalanches should be limited to exposed high terrain downwind of ridges. We expect this hazard to be fairly isolated, but poor visibility may make it hard to spot slopes holding wind-drifted snow. If you see shooting cracks, you've got a clear sign that avalanches are possible on nearby steep slopes.

    Stomp on some safe and representative test features, feel for hard-over-soft or hollow snow, and give yourself a margin around steep slopes below ridgelines unless you can confidently prove them innocent. 

    (12/2/2024)

    This avalanche occurred last season and was human-triggered. This is an example of the type of avalanche you could encounter today on wind-loaded slopes. The steep rollover, or convexity, was a contributing factor in this slide.  

    Photo: Flathead Avalanche Center

Avalanche Discussion

The first phase of this storm left 1 to 4 inches of snow in the Whitefish and Flathead Ranges and up to 8 inches in favored areas of the Swan Range. Precipitation tapered around midday Thursday, after winds peaked in the morning. Since then, wind speeds have generally stayed below transport thresholds.

Today starts relatively quiet, but by mid-afternoon, the real test will begin across the advisory area as a powerful storm arrives. Expect a rapid increase in avalanche danger with heavy snowfall, warming temperatures, and gusty winds. Plan your day accordingly and make a clean exit from the mountains before the storm hits.

If you are out before the storm, the minimal new snow has probably done little to change the avalanche danger in the Whitefish and Flathead Ranges. The Swan Range is less certain. There, the slab is settling and becoming more cohesive, more snow has fallen, weak surface snow was reported before the last storm, and we found a few layers of interest yesterday on a quick snowmobile tour. In other words, while the real test may not have started yet in the Whitefish and Flathead, the first exam of the season may already be underway in the Swan.

With that in mind, add a margin of safety anywhere you find more than about 8 inches of new snow, and remember that even small slides can have big consequences this time of year with so many obstacles exposed or just beneath the surface.

Regioni coperte