Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

Mon
Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
2 · Moderato
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In sintesi

New snow, wind, and a variety of old surfaces will make it easy to trigger avalanches on Sunday. They'll be bigger and easier to trigger where you find blowing snow and drifts at upper elevations. Stay off steep, wind-loaded slopes and use quick tests to watch for places where the snow slides easily.

Problemi valanghivi

  • Storm Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    1–2

    Watch for new avalanches and cracks shooting through the snow as signs of dangerous conditions.  Blowing snow will point to the most avalanche-prone slopes. If you see these indicators, stick to slopes less than 35 degrees. There's enough incoming snow to expect avalanches in both sheltered and wind-exposed terrain. On leeward slopes near and above treeline, you'll be able to trigger avalanches easily and they could be big enough to bury you.

    Even in sheltered areas and below treeline, some slopes may easily break under the weight of a person. Old snow surfaces are variable and some may be weak and slick. Carefully assess the bond at the new/old interface and how it changes as you travel. Use small test slopes and quick, informal tests to see how the snow slides. Watch for reactive conditions on shaded slopes where the old snow consists of a light, low-density layer (possibly facets and surface hoar) resting on a firm, slick layer. This is most likely in areas sheltered from the east wind event that occurred through the 23rd. 

    (2/22/2023)

    Isolated cracking in pockets of wind-drifted snow near Lake Wenatchee. 

    Photo: Brooke Maushund

Avalanche Discussion

On Saturday, observers in the Lanham Lake area found weak snow on most surfaces and they were able to trigger loose dry avalanches. On Thursday and Friday, observers were able to trigger cracks in stiff wind-drifted snow, even in open trees. A few recent avalanches were reported that likely ran in the new snow due to wind loading mid-week. One occurred on an unsupported slope on Mt Index, NE, above treeline. From the 19th-22nd, Stevens Pass received about 1.5 to 2 feet of snow with wind drifting from both east and west winds. 

You can find a couple of crusts in the top half of the snowpack, and you may find some weak snow surrounding them. A thin crust, buried on the 13th is about 2 feet below the surface. We don't expect enough new load of snow for this layer to produce avalanches. It's been almost 2 weeks (February 8-13th) since the last known avalanche on the MLK crust. It's in the middle of the snowpack, about 3.5-5ft below the surface. The adjacent layers have gained strength and test results generally indicate less potential for avalanches. While avalanches on either of these crusts are unlikely, the layers are something to keep an eye on with snow profiles and snowpack tests.

Regioni coperte