Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

Fri
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1 · Debole
Limite del bosco
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In sintesi

Warm temperatures and clearing skies may create wet unstable snow in a few isolated locations especially near rocks and cliffs basking in the sunshine. When you see new rollerballs be leery of traveling on similar slopes.

Problemi valanghivi

  • Loose Wet

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

    We expect the greatest hazard to exist on slopes receiving direct sunshine. This will only occur if the sky clears enough to let the sun start to melt the surface. If clouds continue to hang around, the weather may feel hot and muggy. This will help the snow to become wet and punch no matter the aspect. You could even see some of the few lingering pockets of dry snow on high northerly aspects finally succumb to the heat and develop wet unstable snow. In both instances, shallow spots in the snowpack near rocks and cliffs will be most susceptible to warming. Fortunately, the observation you want to make is the same. If you see new rollerballs be leery of similar slopes. 

    While we expect these avalanches to remain small, as we head deeper into this prolonged warm-up, our uncertainty grows. A foot or more of snow from 1/30 sits above a strong crust. If you see natural loose wet avalanches or if avalanches start to entrain significant snow, the snowpack passed its tipping point and the danger is on the rise.

    (2/8/2022)

    This older loose wet avalanche likely occurred either 2/5 or 2/6. Steep rocky terrain like this is where you're most likely to see isolated pockets of wet unstable snow. LW-N-R1-D1.5-S:  S aspect, 5800', Mt Snoqualmie

    Photo: Dallas Glass

Avalanche Discussion

Over the past several days the snow surface became quite variable. You may find wet punchy snow, icy slopes, breakable crusts, and a few isolated pockets of powder. On Wednesday, Alpental Patrol reported soft wet snow on all aspects and a poor overnight freeze. This could occur again on Wednesday night. Cloud cover should linger into the morning hours limiting the snow surface’s ability to cool and freeze. As a result, you may find wet and punch snow first thing in the morning. Moderate to strong winds during the day may chill the surface in wind-exposed areas and help inhibit thawing on some slopes. However, when it’s this warm, eventually the melting will win. 

Even though the snowpack is generally stable, we’re still talking about and tracking a well-documented layer of weak snow. The Late January Crust-Facets can be found on many shaded slopes below the snow from Jan 30th (12-15 inches). A layer of sugary facets sits sandwiched between two crusts. So far we have not seen any avalanches on this layer at Snoqualmie Pass and snowpack tests have been inconsistent. So, why are we still talking about it? Well, we’re at the beginning of a prolonged warm-up that should last into the weekend. It’s hard to say how these weak grains will react. We should all keep this layer on our radar at least until we make it through this period of uncertainty. On more sunny aspects, the facet-crust sandwich is generally absent and the recent snow sits over a frim layer of spring-like snow. Below these interfaces, a very strong and well-settled snowpack exists. At the moment, we are not tracking any layers deeper in the snow.

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