Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

It is unlikely - but not impossible - to trigger an avalanche 1 to 2 feet deep above 5000'. Avalanches may be larger and more likely on slopes exposed to the wind. When in doubt, defer to lower-angled slopes. 

Avalanche problems

  • Persistent Slabs

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

    Although unlikely, you can trigger a large avalanche 1 to 2 feet deep on a buried weak layer. Weak snow formed during the January drought exists on all aspects and elevations.

    You are more likely to find trouble in areas where the surface snow has settled into a cohesive slab or has been stiffened by wind. Probing or digging are the best ways to determine if a slab has formed above weak snow. Warmer temperatures and new snowfall will continue to consolidate the upper snowpack.

    Slabs will be most sensitive at thin spots near their edges, where rocks stick out of the snow, or convex roll-overs. Collapsing (whumpfing) indicates you found unstable snow. Avalanches may propagate wider than expected or well above you. Choose lower-angle slopes if you have any doubts about what is below the surface.

    (2/13/2025) 

    This small (D1.5) human-triggered slide likely failed on weak snow from January. It occured on a east-facing slope at 6600' which has been both loaded and scoured by shifting wind directions. 

Avalanche Discussion

Snowfall has returned to the advisory area, but meager accumulations and generally light winds will do little to increase the danger today. Still, pay attention to the incoming storm and be prepared to dial back your risk tolerance if you find more snow or wind than expected.  The Flathead Range, Marias Pass, and Swan Lake received the most snow with 4 to 5 inches, so expect hazards to develope more quickly in those areas. 

In the Flathead and Swan zones, we have transitioned from Wind Slab to Persistent Slab.  Here's the rationale:

Recognize that you might still find small reactive pockets of freshly wind-drifted snow along ridges and in open bowls.  Also, recall that wind-affected slopes are among the most likely locations to encounter the developing Persistent Slab problem. Examples include a pair of recent avalanches:

  1. On Thursday, a small (D1.5) slab  was triggered by a party touring outside of WMR. Notice the variable crown depth: this slope has been alternately loaded by southwest winds and scoured by northeast winds during the past week. The slab was likely triggered as the skier traveled over a thin spot. While it was not confirmed, this slide presumably failed on weak snow formed in January, possibly surface hoar. 
  2. In the Skyland area, a natural cornice fall triggered a large avalanche, which then stepped down to a buried weak layer. 

Low-density snowfall and cold temperatures have kept the snow surface loose and dry in many locations. On very steep slopes, riders have (and could continue to) trigger long-running sluffs. These can be hazardous above cliff bands, confined gullies, or terrain traps where the snow piles up deep.

 

Upcoming Events: Check out our calendar and sign up now!

  • February 20-22nd: Avalanche Safety: Introduction to Avalanches Human Powered for Skiers and Snowboarders - register here
  • Feb 26th - Pint Night at Blackstar with donations going to Flathead Avalanche. State of our Snowpack presentation at 7pm! 

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