Avalanche forecast

West Slopes Central

Northwest Avalanche Center
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Avalanche danger

Mon
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Out of date — this forecast expired 3 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Dangerous avalanche conditions continue. Avoiding all avalanche terrain is recommended. A midday transition from snow to rain will make avalanche activity spicier, initiating a shift from dry snow avalanches to wet snow avalanches at mid to lower elevations. 

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    2–2.5

    Multiple natural and human-triggered avalanches were reported in neighboring zones on Saturday. We suspect similar activity occurred in the West Central zone.  More snowfall on Sunday will continue to keep avalanche danger elevated. Avalanche depths and spans could grow, reaching 2-3ft deep or more.  Avalanches will be more reactive in thicker, wind-drifted areas. Steer around all steep slopes and lower-angle terrain beneath steep slopes as well.  

    (12/2/2023)

    A remotely triggered soft slab avalanche in the West North's Baker backcountry from yesterday. The crown was 50-100cm deep. It ran at the new/old interface, on facets. SS-ASr-R2-D2-I. 

    Photo: Phil Straub - Cascade Mtn Ascents

  • Loose Wet

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

    Wet loose avalanches will initiate as rain wets the snowpack. A midday transition of rain up to 5500ft is forecasted.  Rollerballs are your first indicator that snow surfaces are losing strength and wet loose avalanches will follow. Avalanches may start smaller but will increase in size as more rain falls. Avoid steep slopes and the runouts beneath steep terrain. 

    (11/8/2022)

    Example photo: Small rollerballs like these will increase in frequency in size as the snow gets wetter. These indicate wet loose avalanches will likely follow. 

Avalanche Discussion

Avalanche activity was reported by several groups in the West North, Stevens Pass, and Snoqualmie zones on Saturday. Whumphing and natural avalanches were reported. These are all red flags - strong indicators to steer clear of all avalanche terrain. Conditions similar to this or worse, especially with the warming temperatures, are expected to continue into Sunday. 

The presence of weak, faceted snow at the 11/30 interface is causing more avalanche activity in some locations. Facets were found at the bed surface of some human-triggered avalanches. The weakness is most likely to be found beneath the new snow on northerly aspects but we haven't determined how widespread it is. Its presence is a good reason to have a more conservative travel plan if  you want to avoid avalanches. 

Lower elevations are still mainly below threshold, with only a couple feet of snow on the ground. Near the upper reaches of that elevation band as snow amounts increase we recommend more conservative travel choices more akin to the mid elevation band. Travel at mid elevations is improving but the snowpack is still thin. New snow will barely hide early-season hazards that could ruin your day if you encounter them. 

Regions covered