Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Sat
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Out of date — this forecast expired 8 months ago. You’re viewing past conditions, not the current bulletin.

Highlights

Strong winds are building sensitive drifts at elevations above roughly 6000 feet.  You might find these in unusual locations, including mid-slope or areas that are normally sheltered. Blowing snow and shooting cracks are clear signs to move into less steep or more sheltered terrain.

The Northern Whitefish Range was favored by recent snowfall. Expect a higher level of danger in this area.

 

Avalanche problems

  • Wind Slabs

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

    Strong winds are driving today’s danger. Meanwhile, minimal recent snowfall, high rain–snow lines, and limited observations leave some uncertainty as to the exact nature of the hazard. If you're out today, expect blowing snow and fresh wind slab formation above 6000 feet or so. Large slabs are unlikely except on slopes favored by recent snowfall and wind deposition.

    With that in mind, slab depth is your guide today. Use your pole, probe, or arm to check for a cohesive, hard-over-soft layer near the surface. If that layer is deeper than about 8 inches, think carefully before committing to steep terrain, as these deeper pockets could be sensitive. With cranking wind speeds, slabs won’t be only confined to ridgelines—you may be just as likely to find them mid-slope. If you see actively blowing snow (you probably will), wind slabs are forming in real time, and it’s best to avoid nearby steep slopes.

    A few additional considerations for the wind slab problem today:

    • Snow that fell last night and early this morning came in with rising temperatures and is likely upside down, which could increase sensitivity as new slabs form on top of it.
    • Below about 6000’, wet snow and rain from last night should refreeze into a stout crust as temperatures drop this morning. Any drifting on top of that crust may not bond well, but with minimal new snow expected, slab development at these elevations will likely be limited.
    • Stiff slabs of wind-drifted snow can often support your weight and may not give obvious signs of instability (like cracking around your feet or machine) before releasing. These can break well above you and propagate longer distances. 

    (3/10/2025)

    Actively blowing snow is a clear sign that wind slabs are forming and will likely be sensitive. Expect these to form well below ridgeline. 

    Photo: Michael Reavis

Avalanche Discussion

Sadly, we’re once again waking up to far less snow than we had hoped. What little snow has fallen over the past few days has been thoroughly worked over by the wind, and that pattern continues today. As a result, wind-driven avalanche problems are the primary concern.

Wind slabs need two things: wind and snow available for transport. We have the wind in spades; the snow part is less certain. Even a few inches of new snow can be drifted into a foot-deep slab in favored terrain, but the winds over the past few days—today included—have at times been too strong for efficient slab formation. That doesn’t mean slabs aren’t forming (they are); it just means a lot of snow is also being blown into the air, into trees, redistributed far down slope, or perhaps over toward Browning. The net result is many slopes scoured down to hard, crusty surfaces and generally unpleasant travel.

Given the limited snow and extreme winds, slabs large enough to bury or injure a person are likely isolated to places where snow has managed to pile up. In these locations, you could find hard slabs a foot or two thick—or even deeper. Because these slabs are freshly formed and may sit on a crust or upside-down snow, they could be reactive.

As has been the case all season, if you venture far into the highest elevations, expect deeper snow and a corresponding increase in hazard. That said, conditions up high will be brutal today. Visibility is one of the most effective tools for managing a wind slab problem, and I don’t expect much of it today.

Regions covered