Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Out of date — this forecast expired 6 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Expect dangerous conditions at upper elevations after a prolonged storm and avalanche cycle. You can trigger very large and destructive avalanches in wind-loaded areas at upper elevations. Choose simple low-angle terrain and avoid slopes 35 degrees and steeper.

Avalanche problems

  • Storm Slabs

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

    Human-triggered avalanches remain likely on slopes 35 degrees and steeper. The most dangerous conditions exist in wind-loaded terrain at upper elevations where avalanches could break several feet thick and grow very large. Shallower avalanches in non-wind loaded areas may also be easy to trigger and large enough to bury, injure, or kill a person. Seek out supported terrain away from overhead hazard and avoid convex slopes and areas near and below cornices. Carefully evaluate the snowpack looking for shooting cracks, collapses, and recent avalanches. Use small slope tests and hand pits to investigate the recent snow and determine which layers are most sensitive to triggers. Be patient as the snowpack continues to adjust to the massive load of new snow. 

    (01/06/21) Very large avalanches on the north aspect of Table Mountain in the West North zone that ran naturally in the past 24 hours. Photo: Phil Straub

  • Loose Wet

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

    Keep a close eye on steep, rocky, sun-exposed slopes where solar radiation may be strong enough to destabilize snow surfaces and create loose avalanches. Cloud cover may limit solar radiation in the afternoon, and the best chance for strong unfiltered sunshine will likely be in the morning hours. Watch for rollerballs and pinwheels as evidence snow surfaces are becoming wet and weak. Minimize exposure to slopes greater than 35 degrees in direct sunlight and move to shaded terrain to avoid the problem. Loose snow avalanches could be dangerous on their own and even trigger large slab avalanches as they run downslope.

    (01/06/21) Natural loose avalanches on sun-exposed slopes running out of steep rocky terrain above Boulder Lake

Avalanche Discussion

An impressive avalanche cycle occurred during the storm Tuesday night into Wednesday. Large natural and triggered avalanches failed 6-12in deep within the 24-hour storm snow, and very large naturals (D3) were reported in northerly, upper elevation, wind-loaded terrain with crowns several feet thick. Avalanche activity has been ongoing during this heavy loading event, with several rounds of natural avalanche activity over the past week. Precipitation since the new year began has been impressive with copious amounts of rain and snow (over 12in of water recorded at Mt. Baker). Weather stations throughout the NWAC network report snow depths well over 100% of normal for this time of year (Snow Depth Climatology). In addition to dangerous avalanche conditions, non-avalanche hazards exist including tree well and deep snow immersion. Find out more information about deep snow safety HERE.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

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