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Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Slabs of drifted snow up to 2 feet thick remain our primary concern. Avoid dune-shaped drifts and pillowy-looking surfaces while seeking out cold snow on slopes protected from the wind. Be wary of slopes getting hit by the sun and watch for rollerballs and small wet loose avalanches out of steep, rocky terrain features. When you see these signs of instability, move to shady slopes. Plan your exit this afternoon to avoid traveling beneath large south and west facing avalanche paths. 

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2.5

    5 to 12 inches of recent snow and strong winds formed slabs up to 2 feet thick on leeward-facing slopes. Feel for dense snow over soft snow and keep an eye out for shooting cracks. Give drifted features a wide berth and seek out slopes that are not affected by the wind. Look at each slope with a fresh lens because strong winds may have channeled and drifted snow in unusual ways.

    (4/5/2022)

    Part of the crown of a ski-cut triggered soft slab that involved wind-stiffened snow. The crown was less than a foot thick but broke the full width of the slope. SS-ASc-R3-D1.5-I.

    Photo: blase reardon

  • Loose Wet

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

    That ball of fire in the sky will rear its head today. Keep a close eye on surface conditions and be ready to turn to shaded aspects as soon as you feel the surface snow become wet or sticky. Rollerballs or pinwheels are signs of an impending wet loose avalanche cycle. Slides may run long distances and entrain enough snow to become large enough to bury and injure a person.

    (3/24/2022)

    Recent warm temperatures and solar input initiated slides large enough to bury, injure, or kill a person.

    Photo: Mark Dundas

Avalanche Discussion

In the past 48 hours, the forecast region has picked up anywhere from 5 to 12 inches of new snow. Tunnel Ridge in the Flathead Range took the gold medal with 12 inches, Big Mountain in the Whitefish Range took silver with 7 inches, and Noisy Basin in the Swan Range took bronze with 5 inches. During this time, westerly winds cranked; wind speeds averaged between 10 and 30 mph with gusts as high as 70 mph.

Yesterday (Tuesday) Blase and his partner were able to initiate shooting cracks and triggered small slides on leeward-facing slopes (observation). These slides were 5 to 7 inches thick and reactive right below ridgelines and in terrain that funneled wind. Another rider in the Flathead Range found 10 inches of new snow above 6000 feet and active wind transport (observation). This person found the goods in terrain sheltered from the wind.

I would expect slabs to have gained strength over the past 24 hours, but not enough to become trustworthy. Continue to avoid wind drifted aspects and expect strong winds to have drifted snow further downslope than usual. Seek out terrain sheltered from the wind for the safest and best quality riding. You should be able to locate these slopes from a distance by identifying where snow still hangs in trees. 

Solar radiation may wet the snow surface and cause it to slide. These wet loose avalanches will be more of a concern on slopes that somehow got protected from west and southwest winds. Exposed windward aspects will be slow to wet due to a wind-hardened surface. Keep a close eye on cliff bands and rocks that face south and west. These features warm quicker and will be the first to cause rollerballs or point releases. Once those begin, avoid slopes getting hit by the sun.

Join us for our last education event of the season. Topics Class! The Scoop on Spring Touring, tomorrow (Wednesday), April 6, 6:30 to 7:30. No registration is necessary for this in-person event.

We will continue issuing daily avalanche advisories until Sunday, April 10th. After that we will publish snowpack updates on a weekly basis or as needed. As for me, this is my final forecast of the 2021-2022 season. Thank you all for staying tuned and we will see you next year.  Stay safe. 

Regions covered