Avalanche forecast

West Slopes North

Northwest Avalanche Center
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Avalanche danger

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

Very warm temperatures and sun should keep you on the lookout for heightened or dangerous avalanche conditions. Watch out for natural wet avalanches and cornice falls as the day warms. You may still be able to trigger slab avalanches in steep terrain. Avoid trigger points like convex rolls, unsupported slopes above cliffs, or wind-loaded slopes just below ridgeline. 

Avalanche problems

  • Loose Wet

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

    Wet avalanches could occur naturally as the day warms. They may run on east and west aspects at upper elevations and more shaded slopes at low elevations. Stay out from under steep slopes where natural avalanches or cornice falls could come from overhead slopes. Wet avalanches will mostly be small, though seeing one big enough to injure or bury a person isn't out of the question. Use caution around terrain traps like cliffs or gullies where even small avalanches could be dangerous.

    (3/17/2023)

    Two wet avalanches, up to size D1.5, near Slate Mtn, S, 5,400ft.

    Photo: Lee Lazzara

  • Wind Slabs

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

    Westerly wind was strong enough to transport snow on Friday and may've formed shallow, fresh slabs at upper elevations. There are lingering areas where you may be able to trigger slab avalanches about 2 feet down above a crust from the 10th. See below for more info. 

    If you want to reduce the risk of triggering a slab, stick to moderately angled terrain with no unsupported features like convex rolls. You can also steer around recent drifts and pillows of snow on steep, leeward slopes near and above treeline. If pushing into bigger terrain the best you can do is pick slopes with no consequence in the runout.  The warming temperatures raise considerable uncertainty. Consider the consequences of an unlikely cornice fall or glide avalanche release.

    (3/14/2023)

    Human triggered slab avalanche 2-3' deep along the traverse to Shuksan Arm. The bed surface was reported as a crust. Numerous people had crossed the slope in the same area before it finally released in the early afternoon. ESE at 5300'.

    Photo: Geddy Miller

Avalanche Discussion

After weeks of stormy weather and cold snow accumulation, the current warm-up raises significant uncertainty. Very destructive and dangerous avalanche problems like falling cornices and glide avalanches can occur during big warm-ups and they are very difficult to predict. Earlier this week, we received reports of very large avalanches. Plan an extra buffer of safer terrain to account for the uncertainty of the warm temperatures.

A few slab avalanches from earlier this week ran on layers deeper than just surface snow. On Wednesday, a skier sustained serious injuries after being swept off of a cliff by a 2ft deep avalanche on Slate Mtn in the Baker backcountry. You can read the preliminary report HERE. On Friday, Lee Lazzara visited the site of the avalanche involvement and found that the slide ran on a slightly weaker layer of snow above a crust that formed on the 10th. On the 14th, a very large, deep slab was triggered during avalanche mitigation work (The last photo in the gallery below) in extremely steep, unsupported terrain. 

Numerous wet loose avalanches to D2  were reported Tuesday and Thursday. After the weekend, signs of avalanches that released during the peak of the storm were visible everywhere if you looked close enough. Debris piles covered with snow, filled-in crowns, and avalanche paths full of wet, frozen chunks were found throughout the zone on all aspects and at all elevations. New snow amounts range from 2-3' in many areas across the zone. The current warming trend is still affecting and transitioning snow that fell earlier this week and last weekend.

 

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