Avalanche forecast

East Slopes South

Northwest Avalanche Center
View on map

Avalanche danger

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Out of date — this forecast expired 3 years ago.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

Highlights

In areas south of highway 12, slabs could be large enough to ruin your day or worse. Switching wind directions have complicated matters, so assume slopes are guilty until you can reason otherwise and steer around wind deposits on slopes steeper than 35 degrees. Cold dry snow will warm quickly and destabilize in direct sunshine to form small wet loose avalanches.

Avalanche problems

  • Wind Slabs

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

    The East South received a healthy (6-8"?) dose of snow south of Highway 12 and we suspect that upper elevations could have been pushing Considerable on Wednesday. E winds projected these slabs onto the western half of the compass. Winds died down early Wednesday, so these slabs should have 24 hour to settle, but you could still trigger one on a steep, heavily wind-loaded slope or rollover in the terrrain. A shift to increasing W winds Wednesday night that may edge into the moderate range by Thursday will build a fresh round of slabs onto the eastern half of the compass. These slabs will be more sensitive to human trigger, but smaller (we suspect). In some cases these new slabs could bury a thin melt-freeze crust formed by partial sunshine Wednesday afternoon. Wind slabs could also run on the 3/27 crust or old snow interface. Steer around wind-loaded slopes steeper than 35 degrees on any aspect and use inconsequential test slopes to evaluate the slab character wherever you can find them. If you find evidence of recent natural avalanches or experience longer shooting cracks or whumphs, dial back your terrain selection and avoid all open slopes steeper than 35 degrees.

    (3/6/2023)

    Shooting cracks, like in this example, is a sign that you could trigger a wind slab. 

    Photo: Joe Dellaporta

  • Loose Wet

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

    Although the winds will be increasing, we think there's a good chance the strong March sun will win the battle. Expect rollerballs and then small wet loose avalanches as snow sheds off trees and cliffs.  Small wet loose avalanches could gain enough steam atop the 3/27 crust to bury you in a terrain trap such as a creek or gully.

    Example: Wet Loose avalanche on a steep sunny slope. Not how it originated at a point, near trees and rocks.

    Photo: Dallas Glass

Avalanche Discussion

Winter returned to the West south with a healthy 6-8" of snow and 0.8" of water for stations like Green Lake and Gold Hill in the southern portion of the zone. This amount of snow combined with light to occasionally moderate E winds may have stressed any weaker interfaces that exist near or above treeline and it's worth digging to find out how the interfaces in the upper snowpack are responding. Areas north of highway 12 probably only picked up 2-3" of snow and have conditions more similar to Blewett Pass where slabs were quite small and shallow and wet loose mostly inconsequential.

Last week, we saw a decent bit of wind and quite a lot of sunshine. Other than isolated reports of small wind slabs and wet loose avalanches, there also wasn't much avalanche activity or other signs of unstable snow. Southern aspects and lower elevations have thick crusts on the surface in most locations, while true north aspects still hold soft, recycled powder that is beginning to weaken and become faceted. The winds also left wind-packed snow, stiff slabs, and scoured slopes in many locations. With variable old snow surfaces, snow stability from slope to slope may vary significantly. Assess the new/old snow interface as you travel and step into new terrain slowly, assessing conditions before committing to complex terrain where a small avalanche could carry high consequences. 

At mid and upper elevations, a deep and layered winter snowpack exists. If you dig down, you will find older layers of melt-freeze crusts from around Christmas, MLK, and Valentine's day. These layers are not a concern for avalanches at this time but are a reminder that we have not transitioned to a spring snowpack quite yet. For more information about the deeper snowpack, check out my observation from Ahtanum Meadows this past week.

Regions covered