Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

The recent snow is a New Year's treat and has improved the riding conditions. Slabs of wind-drifted snow may be reactive to a rider's weight in favored windy locations. Triggering a large avalanche on deeply buried weak layers remains a concern. Look for cracking in the new snow and stick to slopes 35 degrees or less for a responsible way to start 2023.

Avalanche problems

  • Wind Slabs

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

    Several inches of snow fell Saturday, adding to the moderate amount of snow that has fallen since the Atmospheric River exited our region Wednesday night. Snow is available for transport, but the winds remain unusually quiet. Granted, a couple of stations are rimed, but the remainder generally reports sustained light winds, barely strong enough to drift snow. Expect to find thin slabs in areas just below higher ridgelines favored by wind or below saddles where the wind is funneled and accelerated. Slabs are identified by a pillowed appearance and should be small enough to ride around. You may encounter isolated slabs at middle elevations in areas susceptible to cross-loading, such as John F. Stevens Canyon.

  • Persistent Slabs

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

    The likelihood of triggering a large destructive slide on a weak layer buried near the ground remains possible. This probability increases where the near-surface rain crust formed Wednesday is not thick, strong, and supportable. Aspects, where riders may impact this layer, include wind-scoured or sunny slopes where the snowpack is shallow. Steer around convexities where the stress in the snowpack is concentrated. Sticking to 35 degrees or less slope angles is the most foolproof way to manage this problem.  

Avalanche Discussion

This week looks quiet after two weeks of active weather, which saw extreme temperature swings and bountiful moisture. The storm track is well south of our area, bringing several waves of copious Pacific moisture to California, Nevada, Utah, and Colorado. Widespread Avalanche Warnings are in place, with the Golden State already recording over 10 inches of rain along the Sierra Crest from this system.  To put this amount of precipitation in perspective, our area picked up between 2-3 inches of water from the Atmospheric River, which impacted the Flathead Christmas Day through Wednesday the 28th.

The danger rating for the Flathead peaked at HIGH during the warm, wet weather event but dropped to MODERATE Friday. Seasonal temperatures, light winds, and scattered snow showers look to keep us in this lull through at least mid-week, if not longer. We received eight observations from parties in the Flathead and Whitefish Range Saturday. Thank you! Public observations help make for a more accurate forecast. Most groups noted recent snow totals between 4-18 inches resting on a stout crust formed during last week's rain event. This crust extends to 7200 feet in the Flathead Range, where light to moderate winds transported small amounts of snow, forming isolated small wind slabs. The only signs of instability reported were a bit of cracking in the new snow, one small cornice collapse, and minor collapsing at 6000 feet.

With a New Year upon us, let's look at Snow Water Equivalent amounts for the early 2022-23 winter season. Even though it appears that we are having a banner year, the Flathead Basin is barely above the 1991-2020 median. The FAC forecast area contains 5 SNOTEL sites at low and mid-elevations. Grave Creek and Stahl Peak in the northern Whitefish Range, Flattop in central Glacier Park, Emery Creek near the Hungry Horse Reservoir, and Noisy Bain in the northern Swan Range. All sites are at or just above the median, with Noisy reporting the highest at 126%.

Each Friday, FAC publishes a written Weekly Conditions Summary which can be found in a tab adjacent to the Weather Forecast tab. This is an excellent way to keep up to date with recent Snowpack, Weather, and Avalanche Conditions.

Training: Make 2023 the year of companion rescue skills. Transceiver parks are open at Whitefish Mountain Resort, one at the summit and one adjacent to Grey Wolf. Both are accessible to snowmachines. You can get more details about training and education opportunities events on our events calendar.

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