Bollettino valanghe

East Slopes North

Northwest Avalanche Center
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Pericolo valanghe

Fri
Alta quota
1 · Debole
Limite del bosco
1 · Debole
Sotto il limite
1 · Debole
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In sintesi

Very light snowfall and light winds should freshen up the surface conditions. Small pockets of windslab may be possible on the higher, more exposed slopes. Now is a good time to track near surface conditions before more snow begins to accumulate this weekend. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1

    On the higher, more exposed slopes the new snowfall may drift into soft, shallow slabs. These shouldn't pose too much threat, except in places with extreme consequences. Very steep slopes and hanging snowfields come to mind. Look for shooting cracks and wind textured surfaces as you gain elevation. Small loose dry sluffs could also be possible in some areas. If you find the snow is prone to sluffing, or cracking, than consider routing around more consequential areas. 

    (12/13/2023)

    Example small wind slab on Blue Lake Peak from mid December.

    Photo: Matt Primomo

Avalanche Discussion

Check the new snow totals when you head into the mountains on Thursday. We anticipate 1-3" of new snow at the most, which shouldn't create much hazard. If you find more than this, consider that you may be in an area of heightened avalanche danger. 

On Monday, observers in the Kangaroo ridge area reported firm, wind affected surfaces at very high elevations with minor cracking. They also reported a slightly older and unique glide avalanche (see photo below). It may have occured during warm temperatures on Dec 29th-30th. Recently, observers have found soft, dry snow on sheltered, northerly slopes, with firmer surfaces in sun and wind-exposed terrain. On the 29th, observers in the Hairpin Valley reported moist snow and rollerballs at mid-elevations, with light rime where surfaces stayed cooler. 

Further west near Kitling Peak, an observer on 1/1 and 1/2 reported a much more shallow snowpack than near Washington Pass. He found 3ft at 6,500ft, with less snow overall on top of the thick melt freeze crust from earlier in December. One of the drainages near Swamp Creek had sent rock and mud debris down Hwy 20 for at least a mile westbound. This likely occurred with the atmospheric river in early December. 

It's worth keeping in mind that observers have reported weak layer/crust combinations in the top foot of the snowpack near Washington Pass and Harts Pass. They've found little potential to trigger avalanches where the crusts are thick and the overlying snow is decently bonded. There's uncertainty where the crusts could be thinner and weak layers could be more pronounced, such as at upper elevations and east of the Cascade crest. Now is a good time to track how these upper layers are evolving as we get closer to any significant storm or loading event. For an idea of what you might find in you may find in the southern portion of this zone, like mid-Twisp River drainage, check out these observations from the Holden area.

You can help out by contributing to the forecast. Submit an observation, and let us know what you see! 

Regioni coperte