Boletín de aludes

East Slopes South

Northwest Avalanche Center
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Peligro de aludes

Sat
Alta montaña
3 · Notable
Límite del bosque
3 · Notable
Bajo el límite
2 · Moderado
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Desactualizado: este boletín caducó last year. Estás viendo condiciones pasadas, no el boletín vigente.

Lo esencial

A break between storms will decrease hazard a touch on Friday, but triggering a large avalanche of wind-transported snow in exposed terrain remains likely. Look for red flags that new snow is unstable, such as long shooting cracks from your equipment, audible collapsing, and recent natural or triggered slab avalanches. If you see small bits of snow rolling down on a sunny slope, a small wet snow avalanche could soon follow.

Problemas de aludes

  • Wind Slabs

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

    Small and large sensitive wind slabs were observed in the zone on Thursday. With another dusting of new snow near the Cascade Crest available for transport coupled with cold temperatures, the persistence of these slabs can extend into Friday. A large triggered slab will be running on a slick crust below. Smaller slabs could be running on mid-storm layers that took shape during the system. Wind speeds were reasonably fast during the storm that initiated this problem, so it is possible you could encounter wind-loaded snow at lower elevations as well.

    Wind slabs typically form just below ridgelines and on exposed convexities and gullies. Rippled snow surfaces, cornices, and sharp drifts will be the most helpful visual clues to look for.  Near the Cascade Crest, you may encounter blowing snow, which is a helpful tool to identify where this problem lies as well. Pay attention to the feel of the snow underneath your equipment; a change to denser, pillowy-looking snow indicates the wind carried snow onto that spot.

    (3/13/2025)

    A long shooting crack triggered in wind loaded snow, indicating instability. You can also tell the snow was wind affected due to the rippled surface. (Ahtanum Meadows)

    Photo: Joe Dellaporta

  • Loose Wet

    • Alta montaña
    • Límite del bosque
    • Bajo el límite del bosque
    Probabilidad
    Possible
    Tamaño
    1–1.5

    The sun is high in the sky this late into the season, there is new snow on the ground that weather inputs can easily influence, and it will not be very windy. All this equals the possibility of a wet snow avalanche. Luckily, the sun should be filtered through high clouds, it will be cold and thicker clouds will start rolling through in the afternoon. This will help withhold the impact of this problem. It's unlikely, but not out of the question, to see a wet loose avalanche at upper elevations on similar aspects too.

    The typical initiation of wet loose avalanches involves rollerballs and pinwheels or chunks of snow falling from cliffs and trees. If you're on a sunny slope and the snow is becoming sticky and moist, find lower angle or shadier slopes. 

    (3/9/2025)

    A wet loose avalanche that ran halfway across the groomed sled road. This was on a lower elevation north facing slope.

    Photo: Payton Schiff

Avalanche Discussion

The storm that just rolled through the zone brought a good amount of wind. More importantly, it also brought a much needed winter refresh to the mountains, averaging 5-10" across the zone. Things will be pretty quiet on Friday before another system cruises in Friday night. 

With this lull in the weather, avalanche hazard should be a bit lower than Thursday. But it has been a fairly dynamic few days in the backcountry. An NWAC Forecaster traveled around Ahtanum Meadows on Thursday. He found reactive and touchy wind loaded snow near Darland Mountain. Wind slabs were anywhere from 6" to 2' deep and wind transport continued throughout the day. The bigger slabs were failing on a slick melt freeze crust that formed around 03/05. He also reported wind affected snow on lower elevation slopes in addition to moistening snow in the afternoon below 5300 ft. Avalanche professionals found similar conditions just as recently in the nearby East Central zone. With the lull being short lived, approach the backcountry with continued caution on Friday.

There is was not enough consistent snow coverage below 4500 ft prior to this storm for there to be much avalanche hazard, but previously exposed rocks and stumps might be obscured by fresh snow, so keep an eye out. A small avalanche could knock you over and carry you over hazards like these.

Submit an observation to help NWAC Forecasters reduce uncertainty. It can be short, simple, and even anonymous. Visit the Recent Observations page to get an idea of what backcountry travelers share that helps entertain the forecasts in other zones.

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