Lawinenlagebericht

Snoqualmie Pass

Northwest Avalanche Center
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Lawinengefahr

Sun
Hochgebirge
2 · Mässig
Waldgrenze
2 · Mässig
Unterhalb
1 · Gering
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Kernpunkte

You could still trigger avalanches in wind drifted snow on Saturday. The most suspect slopes will be steep terrain below ridges, the base of cliffs, and confined chutes and gullies. So steer around these features and feel for stiff, hollow-sounding snow before committing to steep slopes.

Lawinenprobleme

  • Wind Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Possible
    Größe
    1–2

    Additional reports of backcountry travelers triggering avalanches came in on Friday. A skier triggered an avalanche above the Cache Couloir near Chair Peak and sustained significant injuries (see additional details in discussion). A separate party triggered a small wind slab at the top of the Cache Couloir. While wind slabs might be a bit more stubborn to trigger on Saturday, these avalanches are examples that it is still possible to find these lingering pockets where you could trigger a slide. Chutes, couloirs, and gullies are likely spots to trigger these wind slabs. Steep slopes below ridges and convex rolls are also potential trigger spots. Ease into the terrain using smaller, less consequential slopes to see how the snow reacts. If you feel firm hollow snow underneath you or see shooting cracks, step back and steer around these suspected wind-loaded areas.

    It may be another clear day tomorrow, and with more moderate temperatures, you may see some wet loose avalanches and roller balls on steep, sunny slopes. Don't let a smaller avalanche knock you over and take you for a ride above a terrain trap. 

    (2/23/2023)

    Confined terrain features like this are likely spots to trigger a wind slab on Saturday.

    Photo: Trevor Kostanich

Avalanche Discussion

A backcountry skier triggered an avalanche above the Cache Couloir. The individual was caught and carried over the cliffs and into the couloir, sustaining significant injuries. The King County Sheriff's Office and Seattle Mountain Rescue evacuated the injured skier by Helicopter.An incoming storm on Saturday will bury the existing snow surfaces. With the recent cold temperatures, weak surfaces may have formed and be our next layer of concern. So take note of what surfaces you find out there on Saturday. A large natural storm slab occurred on Chair Peak on Thursday, and we suspect a cornice fall may have been the trigger. We do not think that this avalanche involved older snow layers. While we expect this avalanche to be the exception rather than the norm, we can't rule out larger storm slab avalanches with the amount of recent snow that has fallen. So slowly approach new terrain and assess conditions before committing to challenging terrain. All observations of recent avalanche activity involve just the recent snow above the rain crust/refreezing wet snow. We are still monitoring deeper interfaces in the snowpack, such as the 2/17 or 2/13 melt-freeze crusts. While we don't suspect these layers to be active, there is still an unlikely possibility of avalanches on these layers. This would most likely occur in isolated areas with a larger trigger, like a cornice or a smaller avalanche that steps down deeper in the snowpack.

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