Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

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Out of date — this forecast expired last year.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

Highlights

New snow may increase the hazard throughout the day. Cracking around your feet or machine is a sign of unstable snow and a cue to seek out simple, low-angle slopes. Though unlikely, small surface slides can trigger a larger avalanche on a buried weak layer at upper elevations.

Avalanche problems

  • Wind Slabs

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

    Recent southwest winds have formed unstable drifts along ridges, in open bowls or in mid-slope gullies. Fresh snow falling under calm to light winds could make visual cues - like an etched surface or dune shaped features - less reliable. Instead, probe or dig in wind-exposed terrain to identify if slabs exist below the surface.

    In areas favored by recent snowfall, it may be possible to trigger small avalanches on slopes sheltered from the wind. These can pose a hazard on slopes with 8 or more inches of new snow or if you are carried into a terrain trap. Use small, inconsequential slopes to test how the new snow is bonding to the old snow surface.

    (3/7/2025)

    Expect to find slabs of wind drifted snow along ridges, in open bowls and especially below cornice. 

    Photo: Rob Millspaugh

  • Persistent Slabs

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

    Triggering a large avalanche that breaks 2 to 3 feet deep is unlikely, but the consequences could be severe. Dig into the snow to identify (and test) weak layers before traveling on or under steep slopes. 

    Layers of surface hoar, facets, and faceted crusts formed in January. These layers produced widespread avalanche cycles in late February.  Weak layers may remain intact and sensitive to the weight of a rider on isolated alpine slopes, where there is not a strong melt-freeze crust from recent warming.

    Hard slabs can break well above you, surprisingly wide, and connect multiple start zones. Likely trigger points include convex roll-overs, rocky faces, or wind-exposed slopes with variable snowpack depth. When in doubt default to simple, low-angled terrain.

    This recent hardslab failed naturally, demonstrating that weak layers cannot be trusted on slopes where they are not capped by a strong crust.  Likely trigger points include convex roll-overs and rocky, wind-affected faces. 

    Photo: Michael Reavis

Avalanche Discussion

A reprise of winter weather continues today. Initially, you are most likely to find trouble on wind-affected alpine slopes or in areas favored by recent snowfall (like the Flathead Range where Tunnel ridge has recorded 8 inches since Monday). As fresh snowfall stacks up, expect new snow problems to creep onto more sheltered slopes and lower in elevation. It may become possible to trigger small slabs or sluffs on slopes that are shaded from the wind. Start to dial back your terrain choices anywhere you find 8 or more inches of recent snow.

A handful of unstable test results (Whitefish, Flathead) and one recent avalanche are reminders of the lingering persistent slab problem. Don’t let your excitement for fresh snow lure you onto steep alpine slopes without knowing what’s under your feet.

Some “springiness” remains: warm temperatures and rain will make it possible for you to encounter wet snow below 6000 feet.  Consider moving off of and out from under steep slopes where you or your machine start sinking into mushy surface snow.    

With cooling temperatures, glide avalanches are less likely but not impossible. Continue to manage this hazard with avoidance:  don’t park, play, lunch, etc. below slopes where glide cracks are present.  Note that fresh snow might make it difficult to spot the usual “brown frowns”.

Curious about recent developments in tele boots and bindings? Check out Telefestivus at Blacktail Ski Area on Saturday, March 22 and Sunday, March 23. In conjunction with the mind-freeing event, Tamarack Brewing will host a fundraiser with a raffle and film for the Friends of the Flathead Avalanche Center from 5 to 8 PM Saturday, March 23. 

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