Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Tue
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Dangerous avalanche conditions exist. Increasing winds will drift new and recent snow into slabs 1 to 2 feet thick at upper elevations. Expect to find thicker and more dangerous slabs closer to the divide. Look for signs of shooting cracks around your board or machine, and pay close attention to blowing snow as winds pick up throughout the day. Your safest bet is to stick to slopes less than 35 degrees and manage your overhead hazard as you climb near or above the upper elevation band.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2

    West and northwest winds will begin to increase throughout the day, blowing at speeds capable of transporting snow. We can expect roughly 10 inches of new snow in the next 24 hours in the Swan Range, Flathead Range, and Glacier National Park. This fresh snow and the soft snow on the surface will transport into firm slabs on the leeward side of ridges and gullies. Avoid pillowy-looking surfaces and areas where you observe active wind loading. Be cautious as you climb into the upper elevations, where stronger winds will build thicker slabs large enough to bury and injure you.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Intense precipitation rates and rising temperatures deposited a dense layer of snow on top of previous low-density snow Saturday night. Over the weekend, observers reported shooting cracks and small avalanches. Expect storm slabs to be mostly stubborn today except where the wind is actively loading easterly facing slopes. These slabs will be larger and more dangerous in the northern Whitefish Range, the Flathead Range, and central Glacier Park, where more snow fell this past weekend.

Avalanche Discussion

An atmospheric river is forecast to impact the southern part of the forecast area today. The Swan Range, Flathead Range, and southern parts of Glacier National Park may see up to a foot of new snow by tomorrow morning. Winds will begin to ramp up to 10 to 15 mph with gusts up to 25 mph. These wind speeds will easily transport snow into thicker slabs on the leeward side of ridges. Although the Whitefish Range shouldn't receive any significant accumulations today, there is still plenty of soft snow sitting on the surface that can get blown into slabs large enough to bury and injure you.

Good and safe riding can be had on slopes below 6500 feet. Below this elevation, watch for shooting cracks and use small test slopes to see how reactive recently formed storm slabs are. If you see signs of instability, dial back your slope angle. Stay out from underneath large avalanche paths, especially ones with an easterly aspect due to active wind loading. If you decide to venture above 6500 feet, avoid areas of active wind loading and stick to slopes 35 degrees or less.

Over the weekend, riders enjoyed powdery winter conditions while seeing an increasing avalanche danger. On Saturday, we received numerous reports of riders observing natural storm slab avalanches, triggering small avalanches, and initiating shooting cracks in the new snow. On Sunday, we issued our first avalanche warning of the 2021/2022 season.  A lack of observations Sunday left us uncertain about how the snowpack dealt with the additional load at upper elevations.

Regions covered