Bollettino valanghe

Stevens Pass

Northwest Avalanche Center
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Pericolo valanghe

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

For Friday, expect small wet avalanches with ongoing warming temperatures and sun. Consider the consequences of a large cornice fall and continue to stay well away from them.

Problemi valanghivi

  • Loose Wet

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

    Watch for triggering wet avalanches, on steep, sun-exposed slopes, especially steeper than 40 degrees. Use caution around terrain traps like cliffs, gullies, or rocks. Avalanches may be easier to trigger and larger at upper elevations. Use small test slopes to check how easily the snow slides. Time your travel to be off of slopes before they are wet and weak. Temperatures will progressively warm with each day this week. Other factors like varying cloud cover, a lack of wind, and the thickness of existing surface crusts will affect how easily you can trigger loose wet avalanches. 

    (3/11/2021) Loose wet avalanches that ran on either March 9th or 10th. On the right side, you can also see an old crown from a deep slab avalanche that ran in late February. Compare to the similar photo below taken on the 8th. Rock Mtn, SE, 6,400ft

Avalanche Discussion

The ongoing warm temperatures will keep a few other considerations on our minds. Don't linger on or under cornices. If you're traveling on a ridge, and give them a wide margin. Consider how a large cornice fall could impact slopes near where you may travel and could trigger otherwise unlikely avalanches. Observations from last week, and more recently in other zones are evidence that the warm temperatures have been dropping cornices. On Sunday and Monday, observers reported a couple of natural wind slab avalanches along with wind transport near and above treeline. 

Deep persistent slab avalanches hold the potential for huge consequences. While these massive avalanches are dormant and unlikely, the snowpack structure can still be found. The mid-January crust-facet layer is now 8-9 feet below the surface and showing signs of strengthening. The last known deep slab avalanche in this zone was on March 1 with another suspected in the West South zone on March 3. Major warming events later in spring and summer could trigger further rounds of avalanches on this layer. Keep in mind the consequences of these massive avalanches and give yourself an extra margin of terrain in and around large avalanche paths.

On March 1st, WSDOT avalanche teams triggered an 8ft deep D3 avalanche on the southeast face of Rock Mountain east of Stevens Pass. In the Chiwaukum Mountains, a natural D3.5 avalanche in upper-elevation north-facing terrain is suspected to have run on the 28th. A massive avalanche (D4) ran naturally in the West Camp path on Rock Mountain less than 2 weeks ago. These are just a few of the very large and historic avalanches that occurred in the second half of February.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte