Avalanche forecast

East Slopes North

Northwest Avalanche Center
View on map

Avalanche danger

Tue
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Out of date — this forecast expired 3 years ago.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

On Monday, you may still be able to trigger avalanches in the recent snow on a variety of steep slopes. Avalanches will be bigger and more dangerous near and above treeline where you find freshly drifted slabs of snow. Avoid steep open slopes with stiff wind-drifted snow and seek out lower-angle or sheltered terrain.

Avalanche problems

  • Wind Slabs

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

    Avalanches will be bigger and easier to trigger above treeline where you find freshly drifted snow. You may find older wind features from west winds. Watch for patterns of drifting to point out the leeward, loaded slopes. Use caution near and below cornices. They've grown large and can fall without warning.The most likely places to trigger wind slabs will be steep slopes below ridges, steep convex rolls, and the base of cliffs. Feel for stiff over soft snow layering and look for signs of cracking to identify areas of unstable, wind-drifted snow. Avoid slopes over 35 degrees if you find the new snow sliding easily or test slopes producing mini avalanches.

    (3/3/2023)

    In specific places like wind lips on ridge lines we could trigger small wind slab avalanches. Upper Twisp River drainage

    Photo: Willie Webster

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1

    In many sheltered areas, you can trigger small avalanches on steep slopes. Loose, uncohesive snow could slide below your feet or machine. While these avalanches often are easier to avoid once triggered, they can be dangerous at times. Be especially cautious in very steep terrain near rocks, cliffs, tight gullies, and other terrain traps. If loose avalanches run particularly fast or are forcefully, take care to stay out of them and not be below the moving snow.

    (3/3/2023)

    A triggered dry loose avalanche.  Upper Twisp River drainage

    Photo: Willie Webster

Avalanche Discussion

On Sunday,  NWAC observer Willie Webster went to the upper Twisp River drainage and reported triggering a small slab avalanche that ran 8-12" deep on the 2/25 crust (see below).  He also reported long-running loose avalanches. Observers reported 2-3 large (size D2) natural slab avalanches on northeast aspects of the Hairpin valley near Washington Pass that likely occurred on Friday. Also on Friday, an observer found about 8" of new snow near the head of the Twisp River drainage.  He was able to trigger small loose avalanches in the surface snow along with some isolated areas of cracking and freshly wind-drifted snow. Below 6,000ft there was little to no cohesion in the new snow.

Near Washington Pass, the Valentine's crust is 2-2.5 feet below the surface. There have been some isolated reports of weak snow adjacent to it, though it's generally not a current concern for avalanches. The January 5th surface hoar can still be found over 3 feet below the surface on many slopes. You may be able to identify the layer as a grey stripe or with planar results in snowpack tests. The layer isn't currently a concern for avalanches.

Regions covered