Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

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

A battle between warm springtime temperatures vs. increasing cloud cover and winds will dictate how the snowpack reacts on Sunday. You’re most likely to encounter avalanches on steep slopes where the surface is wet and sticky. Stay aware of large overhead hazards such as cornices or slopes with crevasse-like cracks where more devastating slides could occur in the warm weather.

Problemi valanghivi

  • Loose Wet

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

    Our warm spell should continue Saturday night into Sunday despite some incoming clouds. This will keep Wet Loose avalanches as the most likely problem you’ll encounter during your travels. It could be a bit tricky with warmer morning air temperatures than Saturday forecasted, but a return of cool easterly winds. These competing weather factors have us thinking that avalanche activity will be more muted than what we experienced on Saturday. Take note if the snow surface is wet and sticky or if you see new rollerballs and pinwheels wherever you’re traveling. Wet Loose avalanches could soon follow, starting at a point and fanning out as they descend. To manage this problem, you should head to shadier slopes, keeping aware of overhead hazards such as cornices or hanging blocks of snow that could release without warning.

    (3/18/2023)

    Wet Loose avalanches on Kendall Peak occurred due to solar input on 3/18. Most originated near rocky terrain.

    Photo: Rachel Gronvold

Avalanche Discussion

Reports rolled in throughout the day of wet avalanche activity on Saturday at Snoqualmie Pass. Most slopes that saw direct sunshine were affected, either producing rollerballs or avalanches up to size D2. Shaded slopes appeared to hold onto mostly dry snow, but trees were shedding and dripping even on the northerly half of the dial. NWAC weather stations at lower elevations soared into the 50s, while upper elevation stations were well into the 40s.

As alluded to above, a poor overnight freeze is expected Saturday night, so we could pick up right where we left off on Sunday morning with wet and sticky surfaces. In contrast to Saturday, we aren’t expecting full sunshine plus we should see a return of breezy easterly winds. This has us dropping the hazard level a notch, but conditions remain largely the same. In general, the snowpack does not like rapid change. Coming out of a recent cold and snowy pattern right into this warm period is considered rapid on a snowpack scale and we could see some unique avalanches as a result. The threat of isolated very large avalanches where blocks of snow such as cornices or glides fail due to the springtime temperatures is still on our radar.

Although the winds will likely be strong enough to drift snow into Wind Slabs on Sunday, there likely isn’t much snow available for transport. On more northerly aspects where the sun’s influence hasn’t been as strong, you could still find well-settled powder with pockets of weak snow. These same aspects also hold some of the more pronounced cornices. If you’re going to encounter a newly formed or lingering hard Wind Slab, it's in those locations. Late in the day, you could even see a dusting of snow up high or a few raindrops down low, but we aren’t anticipating enough to impact the avalanche hazard significantly.

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