Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

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

You could find wet avalanches on all aspects, especially on slopes where the surface snow was previously dry. Minimize travel on and under steep terrain where you observe the initial signs of wet avalanche activity. Look for recently wind-loaded slopes above treeline and steer around steep pillowed slopes.

Avalanche problems

  • Loose Wet

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

    Warmer temperatures and more sun Saturday will maintain the chance of seeing or triggering a wet loose avalanche. The strong sun may be enough to break down surface crusts and initiate wet avalanche activity. Take note of warming and wetting at the snow surface or if previously supportable crusts begin to melt and break down. If you observe signs of instability like rollerballs, pinwheels, or very small avalanches then consider limiting your exposure to similar terrain. Be on the lookout for wet avalanches on any aspect given the high angle of the sun or possible "greenhouse" warming on northerly slopes.

    Watch for snow falling from steep rock slabs features that could initiate avalanches. Pay attention to your surroundings and potential overhead hazard. As warming increases through the weekend, you may see more of this type of phenomenon. 

    Small wet loose avalanche on a northerly slope near treeline. Was likely triggered by warming on April 19th.

    Photo: Adam Ü 

  • Wind Slabs

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

    A new crop of slabs was likely built by gusty winds and light snowfall. Though warm temperatures at treeline limited wind slab development, look for drier snow and more reactive slabs in alpine terrain. Pay attention to the pattern of wind loading as you gain elevation. Filled in tracks, scoured snow surfaces, cornice-like features, changes in snow texture - use these and other clues to suss out where wind slabs could be hiding. Evaluate the bond of wind slabs before committing to steep terrain - or just steer around wind-loaded features to reduce the risk of triggering an avalanche. Watch for falling cornices with increased warming throughout the weekend. Falling cornices could trigger bigger avalanches or be big enough to injure you on their own.

    (4/22/2022) A natural slab avalanche (D2) that likely ran on 4/21-22. NE, 6,500ft, Rainbow Glacier, Mt Baker. Photo: Matt Lubar

Avalanche Discussion

On Friday, Mt Baker Ski Patrol reported triggering small wet loose avalanches on steep sunny slopes around 2p. A few inches of snow that fell Thursday into Friday ran easily on a recent crust. No natural avalanches were reported.

On Wednesday observers in West North reported skier and snowmobile triggered shallow slab avalanches in terrain steeper than 40 degrees. It’s likely that a period of warming in the morning increased slab reactivity, even on northerly terrain. Small wet loose avalanches were observed on most aspects before skies clouded over in the afternoon. Expect to find a crust on temperature and sun affected snow surfaces. Extensive wind transport was noted on the higher peaks with less below 5500'.

There are no new reports of avalanches releasing in a layer of surface hoar that was buried last weekend. That being said surface hoar is responsible for at least one avalanche this week and probably a few more where the weak layer was not visibly confirmed. Though not cause for alarm, the possibility of a surprising avalanche that releases above you or remotely should still factor into your terrain choice on northerly slopes at treeline and above.  If you were to find buried surface hoar it would be on northerly, mid and upper elevation slopes where it managed to survive sun, warmer temperatures, and wind.

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