Bollettino valanghe

Snoqualmie Pass

Northwest Avalanche Center
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Pericolo valanghe

Sat
Alta quota
3 · Marcato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 8 months ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Your chances of triggering an avalanche increase as you climb higher in elevation and later into the day. Unstable snow will primarily be found on leeward terrain below exposed ridges and open slopes, where new wind-drifted snow may slide easily on Thursday’s rain crust. Seek out wind-sheltered terrain or slopes less than 35 degrees.

Problemi valanghivi

  • Wind Slabs

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

    As temperatures cool, fresh wind drifts and wind-loaded slopes will grow through the day on Friday, driven by westerly winds redistributing new snow. These wind effects will be most pronounced at mid and upper elevations. Human-triggered wind slab avalanches will be the main concern, but don't rule out the chance of a natural release from higher, more exposed slopes. A rain crust from Thursday night will provide an excellent sliding surface for any newly formed wind slab to fail on.

    Use small test slopes to identify dense, wind-compacted snow, cracking, or slab failure. Sticking to wind-sheltered terrain will help limit your exposure. Hazard will decrease at lower elevations.

    (12/18/2025)

    A small intentionally triggered wind slab elsewhere in the forecast area. More of these are likely to form with the fresh snowfall.

    Photo: Joe Dellaporta

Avalanche Discussion

In the last 24 hours, 7 inches of fresh snow has accumulated at Pass level. Wind continued to howl, with a 94 MPH gust at 4pm. Cool easterly flow kept temperatures near freezing well into Thursday morning, before snowfall transitioned to rain late in the afternoon. As a result, Thursday’s fresh snow will likely be capped by a thin surface crust before snowfall returns. Expect to find this crust across all elevation bands, becoming thinner with increasing elevation. Lighter-density snow will begin to accumulate Thursday night into Friday as temperatures cool and snow levels drop back to low elevations.

As snowfall continues, low elevations may begin to present low avalanche hazard. That said, the extremely thin snowpack likely poses a greater danger than avalanches themselves. Travel cautiously—Snoqualmie Pass has a long way to go before coverage becomes reasonable. Even a small avalanche could push you into a creek, rocks, or other exposed hazards.

Uncertainty among the forecast staff has been a significant concern this season. Recent extreme weather has knocked out power to weather stations, limited mountain access, and severely reduced field observations. If you’re headed into upper-elevation terrain, be aware that very little information has been collected from these areas. 

The weather over the past few weeks has been extraordinary, with torrential rains, extreme winds, flooding, and landslides. Many communities are dealing with damage to homes, infrastructure, and businesses, stretching resources thin. These events have limited access to the mountains for all of us. State and local resources are working diligently to reduce the worst of these impacts. We can help by being respectful of local communities, obeying road closures, and heeding ski area uphill travel policies.

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