Avalanche forecast

Swan Range

Flathead Avalanche Center
View on map

Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 5 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Dangerous avalanche conditions persist today. On steep, exposed slopes above about 6,500 feet, you can trigger slabs of drifted snow up to 3 feet thick. Slabs large enough to injure or bury you will be less common at middle elevations. Seek out sheltered terrain near and above treeline for safer riding.

Avalanche problems

  • Wind Slabs

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

    Layered slabs of drifted snow formed in the last 48 hours. They will continue to form throughout the day if the snow and wind forecast hold true. Avoid venturing onto open, wind-affected slopes steeper than 35 degrees as you gain elevation. Be careful assessing the hazard in smaller terrain. If you see recent natural avalanches, or get shooting cracks or collapses on test slopes, dial it back and look for sheltered terrain. Slabs will become larger and more dangerous with elevation.

Avalanche Discussion

Howling southwest winds drifted new snow across the region on Wednesday. Natural and human triggered slab avalanches were common near and above treeline in the Flathead Range and the southern tip of Glacier Park. Drifts were less sensitive to cornice drops and ski testing in the southern Whitefish Range where winds and blowing snow were less intense. We haven’t had any recent observations from the Swan Range, which gives me some uncertainty about avalanche activity there.

On Tuesday, Mark reported similarly windy conditions in the Apgar Range  and small but sensitive drifts in usually sheltered areas. Skiers in John Stevens Canyon reported reactive wind slabs 10-14 inches thick above 7,000 feet.

Most of the slabs reported over the past few days failed on low density storm snow. However, we saw a break in precipitation and cloud cover Monday (which has been unusual this December). Cold clear conditions may have allowed near-surface facets to form in the Flathead Range and Glacier Park. An observer in the Swan Range found small surface hoar on easterly aspects up to about 5,600 feet. Those observations suggest recent wind slabs may be resting on weaker snow in some areas. Both of these scenarios can make conditions that are less predictable than you’d think. 

Regions covered