Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
Vedi sulla mappa

Pericolo valanghe

Sat
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
Open full map
Non aggiornato — questo bollettino è scaduto 5 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Recent warm and sunny weather has started to produce wet avalanches at Snoqualmie Pass. Another springlike day on Friday could help more slopes reach their tipping point. If you are standing in wet and sticky snow, think about wet avalanches on sunny slopes over 35 degrees.

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. A change from firm and icy to wet and sticky snow may be your first indication that the springtime weather is winning the battle and 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.

    (2/10/2022)

    This natural Wet Loose avalanche on Thursday (2/10) initiated at a point near rocks and grew larger and fanned out as it descended downhill. 

    Photo: Robert Hahn

Avalanche Discussion

Both NWAC observers and recreationalists reported Wet Loose activity at Snoqualmie Pass on Thursday. The top 6-8” of snow was easily triggered by skiers and running far on steep sunny slopes near the head of Commonwealth Basin. Over near Source Lake, a natural Wet Loose avalanche initiated near rocks before fanning out as it descended. In both locations, surfaces were found to be highly variable depending on aspect, elevation, and solar input. Ice, springlike snow, and wind-pressed snow have all been found in close proximity, sometimes on the same slope. 

Thursday night will be another night of above freezing temperatures, but this time 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 snow should soften throughout the day, but that will depend on how cool east winds develop. Our expectation is that the wind will not be enough to keep wet avalanches at bay. That said, watch the weather for yourself. If you find that you are in a cool and breezy area, surfaces may stay firmer resulting in locally lower hazard.

All avalanche activity should remain above the Late January Crust, which can be found about a foot below the surface. 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 during this cycle, 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 glide or 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