Avalanche forecast

Flathead Range & Glacier NP

Flathead Avalanche Center
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Avalanche danger

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

Unusually windy conditions continue forming fresh slabs and thickening existing slabs. You can trigger an avalanche 1-3 feet thick on mid and upper-elevation slopes affected by the wind. Choose terrain sheltered from the wind for a safer and more enjoyable experience.

Avalanche problems

  • Wind Slabs

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

    Over the past 48 hours, impressive wind speeds were recorded in all three forecast zones. Yesterday's observations included blowing snow and large swaths of wind-affected snow. Southwest winds have drifted recent low-density snow into fresh cornices and slabs on leeward slopes at both mid and upper elevations.

    Slabs will increase in thickness and become more dangerous as you gain elevation. Look for slabs near and below ridgelines, on the sidewalls of cross-loaded gullies, or around prominent rock outcroppings. A rippled surface or dune shape formation may identify these wind features. Older, harder slabs may feel and sound hollow like a drum. Slabs are generally denser than the surrounding snow and may keep you or your machine from sinking into the snow.

    Cracking in the snow surface beneath you is a sign directing you to seek out sheltered terrain for a safer, higher-quality experience.

    (2/3/2023) Wind Photo: Brad Taylor

  • Persistent Slabs

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

    Observers continue to find buried facets and surface hoar in snowpits. These weak layers are gaining strength slowly but continue to be a concern. This layer is 1-2 feet below the surface in the Flathead Range and Southern Glacier Park and 1-3 feet below the surface in the Swan Range. This layer has been found in most aspects but is most developed on NW-NE-SE slopes.

    The only way to identify this hazard is to dig down and see if this weak layer is present. Where you find it, choose lower-angle terrain free of overhead hazards and convexities. Small avalanches have the potential to step down to buried weak layers.   Slopes with clean runouts are an excellent way to build a margin of safety into your day.

Avalanche Discussion

Recent weather: The storm forecast for overnight underproduced the expected precipitation, with just an inch or two throughout the area and light snow showers expected today. Unfortunately, the storm delivered another round of damaging winds. Moderate sustained wind speeds with strong to extreme gusts were recorded in all forecast zones over the past 24 hours. Gusts reached 64 in the northern Whitefish Range, while our windiest station, Aeneas Ridge in the Swan, recorded sustained speeds of 35 mph with a gust up to 67. Elevated winds continue through the morning before tapering off this afternoon. Sunshine and warm temperatures over the past two days moistened the snow surface on sunny slopes sheltered from the wind up to 6200 feet.

Observations: Yesterday, observers noted large swaths of wind-affected snow in areas open to the wind. Blowing snow was noted along with cornices sensitive to the weight of a skier in the Swan Range, Flathead Range, and the southern Whitefish Range. Areas sheltered from the wind and sun maintained up to 30 cm (12 inches) of dry, cohesionless powder. A thin (~2 cm) breakable sun crust was encountered on steep southerly slopes from Thursday's warming. This morning, we expect a more widespread breakable surface crust on sunny aspects. Recreationalists on the west side of the Swan Range noted several glide cracks that are opening.

Today's Conditions: Wind Slab remains problem number one as sustained south-southwest winds form slabs on leeward aspects at mid and upper elevations. Fresh slabs will thicken existing slabs formed over the past few days. You should expect to find soft and hard slabs if you travel in areas exposed to the wind. Soft slabs generally warn of their presence as they tend to crack beneath you or your machine. Hard slabs are a much more dangerous beast as they support your weight, and cracks are often not observed beneath you. Instead, they may break above you and propagate much wider than a soft slab. 

Come one, come all! Flathead Avalanche Friends Fest, a four-day festival from Feb 8-11, has a full schedule with mini-clinics, a keynote speaker, après, and a Big-A$$ Raffle. A little something for everyone. We hope you can join us to celebrate our community, learn about snow, and support our safety mission. Learn more here.

Motorized Level 1 - Instructed by Eric Knoff and Six Points Avalanche Education from Tuesday, February 7, 2023, to Thursday, February 9, 2023. More details are here

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