Boletín de aludes

Snoqualmie Pass

Northwest Avalanche Center
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Peligro de aludes

Sun
Alta montaña
4 · Fuerte
Límite del bosque
3 · Notable
Bajo el límite
2 · Moderado
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Desactualizado: este boletín caducó 2 years ago. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

Strong winds, mixed precipitation and fluctuating freezing levels all point toward a stormy day at Snoqualmie Pass. You may not encounter much avalanche danger when you step out of your car, but it will become very dangerous as you ascend. Keep your trip plan simple and be leery of slopes over 35 degrees regardless of your elevation.

Problemas de aludes

  • Storm Slabs

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Very Likely
    Tamaño
    1–2

    Upper elevation slopes will rapidly load due to heavy snowfall and strong winds. Widespread natural avalanche activity is expected at these elevations, many of which will be large enough to bury or kill you. It's shaping up to be a good day to play around in the flats or trees, avoiding all terrain where avalanches can start, run, or stop.

    Due to Friday's warmup, snow could get "caked in" and bond well to a moist surface at lower elevations, helping to curb natural activity. Don't take that to the bank, though. Anywhere you see winds moving snow into thicker drifts,  surface cracks, or new avalanche debris, get out of there!

    (12/26/2024)

    A storm slab triggered by explosives during morning mitigation efforts at the Summit at Snoqualmie on 12/26.

    Photo: Summit at Snoqualmie Pro Patrol

  • Loose Wet

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–2

    Rising freezing levels during the daylight hours will result in a switchover to rain.  This could result in wet avalanches on steep slopes. The elevation to which rain will reach is hard to pin down, but avalanche activity will be more likely in areas where rain falls on cold, dry snow for the first time. Unfortunately (or luckily, depending on your outlook on life), surfaces got wet on Friday up to 5000 feet around Snoqualmie Pass. That could help to keep these slides in check. If you see new rollerballs and pinwheels or fan-shaped avalanche debris, head for lower-angled terrain, keeping aware of what's above you.

    (12/27/2024)

    Small wet loose avalanches that occurred naturally during the day on 12/27 as temperatures bumped up and rain fell on dry snow.

    Photo: Andy Harrington

Avalanche Discussion

After a "relative lull" on Friday, we're back to stormy conditions on Saturday. This will be another big storm pulse, capable of delivering feet of snow accompanied by strong winds. This storm has all the ingredients for natural avalanches - strong winds, heavy snowfall, and rising freezing levels. 

It's been a very stormy week, with widespread avalanche activity reported on Thursday. The generally warm temperatures over the last few days have helped that snow to settle quickly. However, numerous interstorm layers were identified by NWAC forecasters on Friday on Kendall Peak. Although none of these interfaces were all that alarming, they broke consistently in small column tests. They could get overloaded by the incoming storm and fail on Saturday. We expect all avalanche activity to be confined to the snow above the Solstice Crust. As of Friday afternoon, this stout interface was roughly 2-3 feet below the surface at mid-elevations.

On Friday, the snow surface got wet up to roughly 5000 feet. Small wet avalanches were observed by NWAC forecasters and backcountry travelers. A wet surface could lead to a good bond with the new snow and help limit avalanche potential on Saturday to a degree. However, above 5000 feet our hunch is that bond won't be as favorable. 

Coverage at lower elevations has vastly improved this week. We're no longer talking about ice or bare dirt. We're still dealing with plenty of hazards though - open creeks and heavy wet snow being the main culprits. 

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