Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Strong winds have drifted the recent snow into slabs that a rider could trigger. Even a small slide has the potential to step down into a deeper weak layer, producing a much larger avalanche. Steer around pockets of wind-drifted snow and think twice about steep, shaded slopes above 6000’, where those buried weak layers remain a concern.

Avalanche problems

  • Wind Slabs

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

    Winds have been and will continue to crank today, drifting any available soft snow into slabs that may remain sensitive to your weight. These slabs may have been pushed farther down slope than you might expect. Softer, more sensitive snow may reside lower on the slope, while harder, more stubborn (but more dangerous) slabs sit closer to the ridgeline.

    Use small, low-consequence test slopes to check for reactivity—shooting cracks from your feet or machine are clear red flags. With good visibility in the forecast, look for textured snow, pillowy drifts, and active blowing snow as signs of recent loading.

    Outside of the northern Whitefish or the highest elevations of the Flathead, wind slabs are unlikely to be large on their own. The bigger concern is that even a small slab or cornice fall could step down into the January Drought Layer, producing a large and destructive avalanche (see Problem 2, below).

    An example of a crossloaded slope from earlier this season. With strong recent winds, wind slabs won't be relegated just to the ridgeline today. Look for wind-loaded pockets on the downwind side of gullies.

    Photo: Flathead Avalanche Center

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3

    3 to 5 feet below the surface—and deeper in wind-loaded start zones—is the January Drought Layer (JDL) of surface hoar. The JDL was producing big avalanches before the warmup,  and continued to do so during the warm spell, with wet slabs releasing where water reached it and dry slabs elsewhere. As water continues to move through the snowpack, more slopes may follow. Whether dry or wet, the layer remains dangerous—large, connected slopes could fail wall-to-wall, producing wide, destructive avalanches. At the same time, it’s becoming harder to pin down what, exactly, would tip it over. Today, it will probably need a shock load like a cornice fall or surface-snow avalanche. I believe the odds of triggering a slide on the JDL today are low, but the consequences remain severe.

    Avoidance is still the only surefire way to keep safe. Low-angle shaded slopes may still hold soft snow, while west through south aspects offer a safer option if you’re seeking steeper lines. If you step onto a steep shaded slope, stack the odds in your favor: avoid recently wind-loaded terrain, give wide margins to thin spots like rock bands and trees, and prioritize slopes with clean runouts—easier said than done in northwest Montana. 

    (3/20/2026)

    Just one part of the crown of a very large dry slab avalanche along the peaks south of Hash Mountain. Step downs from shallower slabs of new/drifted snow are visible above the thicker crowns.

    We presume this failed along on the January Drought Layer. Deepest part of the crown appears to be 6-8 feet deep.

    Photo: Guy Zoellner

Avalanche Discussion

We’re in the midst of an uneven transition to spring. Ideally, we would get a sufficient warmup, all at once, to put water on the JDL at all elevations, avalanche whatever is going to avalanche, and let us put this problem to bed. But that’s not the hand we’ve been dealt.

Spring’s transition often plays out on a slope-by-slope scale, and we can’t see what’s happening below the surface. Tiny differences in snowpack structure can drastically change how water moves through the snow. Some slopes have already seen water reach the JDL, and if they were going to produce wet slabs, they likely have. Others haven’t yet, and we’ll have to wait and see. Even where the layer is still dry, shock loads can still trigger a release.

All of this adds up to significant uncertainty, especially at upper elevations. The good news is the snowpack is primed: the next substantial warming is more likely to push water down to the JDL and trigger its “swan song.” That said, such a warming doesn’t appear imminent. This weekend could generate some meltwater, but it looks short-lived, with a return to winter conditions soon after.

Moving forward, cold or cool days following strong overnight freezes carry a lower risk of triggering the JDL. When warming does occur and meltwater is produced, it’s especially important to give steep slopes above 6,000 feet a wide margin. 

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