Avalanche forecast

East Slopes South

Northwest Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 2 years ago.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

Highlights

New snow, strong winds, and an unusually weak upper snowpack will make for a dangerous Saturday. While you'll be able to trigger the largest avalanches in wind-drifted snow, don't underestimate steep, open slopes in wind sheltered locations either. Let the storm run its course and seek out slopes less than 30 degrees. 

Avalanche problems

  • Wind Slabs

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

    Wind slabs could be large and ripe for human-triggering on Saturday morning.  SW winds have been cranking and redistributing new snow along leeward slopes around the zone. Due to these high winds, don’t be surprised to find these dense slabs further down slope than usual or on mid-slope convexities. Some of these wind slabs could break in surprising ways or propagate widely if they fail on weak, faceted snow at new/old snow interface.

    Expect these wind slabs to lurk on the downwind sides of ridges, below cornices, on mid-slope convexities, or adjacent to rocky-cliffy terrain. However, Saturday won’t be the day to sneak around wind loaded slopes. Just consider avoiding this type of terrain altogether. You can use visual clues like blowing snow or surface textures like ripples, dunes, and pillow-like slabs to help you identify features of concern. Shooting cracks and recent avalanche activity are great reasons to dial it back and seek out more sheltered terrain. 

    (1/31/2025)

    Cornices and actively blowing snow in the Crystal Mountain area. Despite low storm totals at this hour, the wind was already moving it into slabs on leeward slopes.

    Photo: Andy Harrington

  • Storm Slabs

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

    The East South is getting just enough new snow that triggering avalanches in more sheltered terrain is not out of the question, especially on slopes that harbor faceted snow at the new old/snow interface.  Prior to this storm, backcountry observers reported everything from crusts, to near-surface facets and surface hoar on many slopes. New snow will bond differently to these surfaces and avalanche activity may not be consistent from slope to slope. 

    Due to this variability at the old snow surface, snowpack tests and test slopes may not paint the full picture. You’ll want to collect information from many data points during your tour and simplify your terrain. Avalanches could break in surprising ways if they fail on faceted grains or surface hoar, especially at middle elevations. Saturday will be a good day to keep your margins wide and enjoy the new snow in mellow terrain. 

    (1/31/2025)

    An example of a storm slab on Friday in the West North zone. 

Avalanche Discussion

The January drought has ended and old man winter has finally returned. With that, be ready to take a big step back with your terrain selection. The recent dry weather was a great opportunity to ride higher or ski steeper terrain with good snowpack stability, but that is no longer the case.  An impactful storm and uncertainty around recently buried weak layers are good enough reasons to dial it back and enjoy mellow powder skiing or riding until the storm has run its course. Prior to this storm, avalanche forecasters and backcountry observers consistently reported weak facets on north - east aspects at all elevations. Other aspects held facets, but also more surface crusts. The extended dry spell is unusual for the Pacific Northwest, so be suspicious of the snowpack as new snow continues to fall in the coming days. 

 Multiple long-time avalanche professionals have mentioned that the last time we had a similar snowpack was in 2017-2018, which resulted in 7 deaths throughout the Cascades in roughly a week. You can read the accident reports here to re-familiarize yourself. Needless to say, many professionals are on edge about how the next few weeks are going to play out. 

Observations help fuel a more accurate avalanche forecast. Let us know what you see by submitting an observation here.

Regions covered