Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

Springlike weather with temperatures well above freezing could produce wet avalanches on steep sunny slopes on Friday. Keep an eye on how the weather is changing the snow surface throughout the day. Once it gets wet and sticky, consider heading for lower angled or shadier slopes.

Problemi valanghivi

  • Loose Wet

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1–1.5

    Continued sunny and unseasonably warm weather will battle some cool winds in an attempt to destabilize the snow surface on Friday. This could be easier to achieve on the volcanoes where warmer temperatures and less wind is expected. Regardless of your location, take note if the snow surface changes from firm and icy to wet and sticky. Once this happens, you’ll know that Wet Loose avalanches are possible. If you are sinking into the snow deeper than your ankle, or notice precursors to wet avalanches such as rollerballs and pinwheels, it may be time to head for shadier terrain. Wet Loose avalanches will be more likely on slopes over 35 degrees that see direct sunshine and often start at a point before fanning out and growing in size as they descend. These avalanches could initiate more easily in shallow areas of the snowpack, such as near rocks and cliffs, and should be larger and easier to trigger as you ascend in elevation. 

    (2/9/2022)

    Triggered rollerballs on an E-facing slope. This is a great sign that the snow surface is becoming wet and unstable. 

    Photo: Andy Harrington

Avalanche Discussion

Thursday night will be another night of above freezing temperatures, but the skies should be mostly clear. This could allow the surface to freeze from the top down and possibly help with stability first thing in the morning. The question mark for Friday will be the effect of the east winds. In areas closer to the crest that are more susceptible to these cool breezes, the snow may have a more difficult time softening. Closer to the volcanoes, warmer temperatures and less wind should allow the snow to soften throughout the day. You will need to see how the weather is unfolding in your location and then look at the snow surface to determine the likelihood of triggering a wet avalanche on the slope you are on. Surface conditions are variable across the zone, and dependent upon aspect, elevation, or the presence of sunshine. Multiple reports indicate ice, spring snow, and wind-pressed snow all within close proximity, even on the same slope. 

All avalanche activity should remain above the Late January Crust, which can be found up to a foot below the surface in some locations. We are continuing to keep an eye on this interface where weak snow has been found in a “crust-facet sandwich”. These persistent grains shouldn’t come into play in the near term, but the crust could provide an excellent sliding surface if avalanches are able to reach this depth. It could take a large trigger such as a cornice fall during this warm weather to get deeper avalanches, so put plenty of space between you and hanging blocks of snow and ice above you as you travel. Of course, if you travel into larger and more consequential alpine terrain, the potential for larger and more consequential avalanches goes hand in hand with your decision.

Regioni coperte