Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

Today’s avalanche problems are generally small and easy to manage. Expect to trigger Dry Loose avalanches in very steep, northerly-facing terrain. Slabs of drifted snow exist downwind of exposed ridgelines above 6500 feet. Steer around pillowy-looking surfaces and dune-shaped drifts.

Avalanche problems

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Manage your sluff with defensive riding strategies if you travel into very steep, northerly-facing terrain that is sheltered from the wind. One defensive riding strategy that comes to mind is to cut across the top of the slope and allow your sluff to run before continuing your descent. Dry Loose avalanches will generally be harmless in size, yet could prove consequential if knocked off your feet above cliff bands or other terrain traps. It is best practice to expose only one rider at a time to steep terrain.

    A report of a freezing rain crust came in this morning. A thin surface crust will eliminate the chances of triggering a Dry Loose avalanche. 

    (12/24/2023)

    Note the descent path of the lookers right track. This type of descent allows your sluff from each turn to run next to you, vs. over you. 

    Photo: Pete Costain

  • Wind Slabs

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

    Expect to find slabs up to 1 foot thick on wind-loaded terrain features at upper elevations. These terrain features include slopes below exposed ridgelines and on the sidewalls of gullies. Slabs of drifted snow should be stubborn or unreactive to triggering, however, that does not suggest putting the blinders on. Continue to keep an eye out for textured surfaces and dune-shaped drifts. Signs of cracking around your board or machine should steer you to areas sheltered from the wind.

    Varying wind directions over the last few days formed slabs of drifted snow on most aspects at upper elevations. The painted distribution identifies the most recently formed slabs. Slabs that formed on south and west aspects this past weekend should be unreactive to trigger.

    (12/17/2023)

    Cracking around your boards or machine are signs you've found a slab. Although unlikely, keep an eye out for signs of recent drifting. Test them on inconsequential slopes before commiting to larger slopes. 

    Photo: David Kerner

Avalanche Discussion

Most days an avalanche forecast is only as good as a weather forecast. Yesterday was one of those days. Cloud cover opened to clear skies and freezing levels climbed higher than expected, resulting in a round of natural loose wet avalanches on sunbaked slopes. So far, reported avalanche sizes were primarily small (D1), with a couple of large (D2) slides in longer running paths. Expect to find a sun crust on south and west aspects.

Reports of rider-triggered Dry Loose avalanches continue to trickle in, hence the reason for bringing it back to the problem list. This problem is primarily listed for those of you looking to ride in very steep terrain. Since solar aspects were cooked by the sun yesterday, I’d expect this problem to be confined to shaded slopes at middle and upper elevations. Any triggered avalanche should be predictable and easy to manage with slope cuts or other defensive riding strategies.

Wind speeds over the last 24 hours were calm and variable. Slabs of drifted snow will be two to three days old and difficult to trigger. Tuck in below or ride around wind-drifted slabs if your travels take you high into the alpine or into consequential terrain.

We removed Persistent Slab as a listed hazard on Monday. You can still find soft facets around a hard crust on many middle and upper-elevation slopes. Recent warm temperatures allowed these facets to gain strength. A supportable crust near the surface also adds strength to the snowpack by reducing the chances of collapsing the weak layer. If your travels take you to the highest elevations in the forecast area, it is still worth digging to look for this structure, especially if you don’t find a supportable crust beneath your feet or machine.

Regions covered