Avalanche forecast

Swan Range

Flathead Avalanche Center
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Avalanche danger

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

It is possible to trigger an avalanche today on steep slopes above 5000 feet. The danger will be highest in exposed terrain holding deeper and stiffer slabs of wind-drifted snow. Shooting cracks, hard over soft snow, and blowing snow are all signs to move to a lower-angle slope. 

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.

Avalanche problems

  • Storm Slabs

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

    While the most likely place to trigger an avalanche today is in wind-loaded terrain near ridgelines, the Swan has picked up enough recent snow in favored spots to put avalanches on your radar even in wind-protected terrain if you find more than 8 inches of new snow. With some uncertainty about the surface these slabs are sitting on, they could propagate more widely than you might expect, and that potential will grow as the slab gains cohesion. In the wind zone, slabs could reach a few feet deep. Poor visibility will make it tough to visually assess for wind slabs in exposed areas.

    Stomp on safe, representative test features to see how the snow reacts, feel for hard-over-soft or hollow snow, and give yourself a margin around steep slopes below unless you can confidently rule out any instabilities.

    (3/2/2023)

    An example of a slab avalanche below a ridge line. While avalanches in wind-loaded terrain are the most likely hazard today, soft storm slab avalanches are possible where you find more than 8" of new snow.

    Photo: md

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 jump in avalanche danger with the mix of 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 recent 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.

Regions covered