Bollettino valanghe

Flathead Range & Glacier NP

Flathead Avalanche Center
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Pericolo valanghe

Wed
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

There is still a chance of triggering a large avalanche, despite recent hardening of the surface from wind and a mix of rain or snow. Seek out gentle slopes that are protected from the wind and disconnected from steep slopes above you, in order to build in a margin of safety.

Problemi valanghivi

  • Persistent Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    2–3

    Evidence of instability on a variety of weak layers and large natural avalanches continues to be reported daily. Recent wind and precipitation incrementally added depth and weight to a hard slab sitting 1 to 5 feet above weak layers. A supportable crust exists on all aspects and elevations up to about 6,500 feet. Expect this crust to thin and/or disappear as you gain elevation, above there recent wind-transported snow will take over the additional loading. 

    Don’t let the fact that you’re on a supportable crust lure you onto a suspect slope. The weak snowpack structure should guide your travel plans. Steep slopes that face NW-N-S are still to be avoided. Find safer, better-riding conditions where the wind has less effect, and the slope angle is gentle.

    Snowpit test scores continue to show sensitivity within several weak layers.

    (3/9/2026) Northern Swan, 6500', N aspect Both of the persistent buried surface hoar layers failed in stability tests. mid-Feb, ECTP15 JDL, ECTP19 Photo: chris gotschalk

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–2

    Recent, upper elevation snow and wind loaded typically leeward (NW-N-SE) slopes. Afternoon snow and wind will continue to build fresh drifts below ridgelines and crossload mid-slope terrain. 

    Look for the common clues of shooting cracks under your feet or a drummy sound to the snow you’re on. If you notice either of these, move to a more protected area.

    Slopes that are being loaded by winds are also the most prone to harboring a Persistent Slab problem. Be aware that a smaller avalanche involving recent wind-driven snow may step down and trigger a much larger, more destructive avalanche.

    Recent winds have loaded areas below ridgelines and cross-loaded mid-slope areas as well.

    (3/9/2026) Photo: Michael Reavis

Avalanche Discussion

An Atmospheric River is set to impact the region starting late Wednesday. Very dangerous conditions will likely develop as new snow and wind-drifted snow loads a weak snowpack. Stay tuned as information about this storm becomes clearer. 

We continue to receive reports of very large (D3) natural avalanches from the Swan and Flathead ranges. The majority of avalanches are failing on north and east aspects at around 6500 feet. Yesterday (Monday), Cam and Mike found that the surface had refrozen into a hard, supportable crust.  Traveling on a supportable crust can reduce the chances of collapsing a weak layer further down. Although that is often the case, we still recommend giving steep slopes plenty of space for the time being. Snowpack tests continue to show propagating test scores with hard force, and the majority of the recent avalanches would be unsurvivable. 

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