Bollettino valanghe

West Slopes Central

Northwest Avalanche Center
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Alta quota
3 · Marcato
Limite del bosco
3 · Marcato
Sotto il limite
3 · Marcato
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In sintesi

Strong sun and very warm temperatures produced numerous large avalanches in the last few days. Expect continued avalanche activity on Sunday. There is no precise way to predict exactly where, when, and how many will occur. The only way to reduce risk is to avoid traveling on and under steep slopes, cornices, and rocky terrain that could shed snow. 

Problemi valanghivi

  • Wet Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Likely
    Dimensione
    2–3

    We are going into the fourth day of temperatures well above freezing. Cornice falls, wet loose, wet slab, and glide avalanches are all likely. The peak of wet avalanche activity will vary across the forecast zone. Some locations have already seen widespread avalanche activity, while others are ready to produce plenty more. It’s impossible to predict where and when any of these will occur. The only remedy is to stay out of the way. 

    Stick to low-angle slopes with minimal exposure to steep terrain overhead.  Don't linger in gullies that connect to avalanche terrain above. Don't have lunch under glide cracks, sagging cornices or blocks of melting snow clinging to rock faces. There is little reason to recreate on steep slopes as the snow becomes even more sticky, gooey, and unsupportable. Travel conditions continue to deteriorate. It’s worth noting that small avalanches or cornice falls can trigger a much larger avalanche lower on the slope.

     

    (3/16/2024)

    Fresh slab and wet loose avalanches on the west side of Loomis Mountain near Mt. Baker at 4900'. The crown is visible, intersecting the sun-shadow line below a cliff, in the center of the photo.

    Photo: Irene Henninger

Avalanche Discussion

Given the current weather pattern, it's unlikely you would find a slab of dry snow in which to trigger an avalanche except for at the highest elevations. If you do make it to the alpine where cold snow still exists, lookout for pockets of wind slab in steep terrain, especially on slopes with consequences like cliffs or rocks in the runout below. Snow plumes were observed on the north side of Baker on Saturday morning. There is still some dry snow up high on shady aspects to drift onto leeward slopes.

With the number of large wet avalanches observed in the past few days, it’s getting tricky to say exactly when many of them occurred. Observers all over the Cascades reported natural and human-triggered avalanches on most aspects. While many were small, some wet loose avalanches that initiated in steep, alpine terrain exceeded D2 in size. Glide cracks are opening up, and cornices are starting to sag. While not an unprecedented amount of avalanche activity, there is enough to reinforce the idea that now is not the time to be moving in an around big, steep slopes - unless you are OK with much higher risk than normal.

Saturday was another scorcher in the mountains, with most mid-elevation weather stations showing high temperatures in the upper 50s. The White Chuck Tripod near Darrington reached 60F at 1 pm. Alpine winds kept some upper-elevation terrain slightly cooler in neighboring zones, and the same is probably the case for West Central. Expect minimal wind on Sunday. While clear skies overnight might allow for a shallow refreeze, don’t expect it to last long in most areas. 

The Cascades are feeling the effects of a stretch of very warm, sunny weather. It is the first big, spring-like warming event of the year, with high temperatures in the 50’s and freezing levels over 10,000’. Very warm conditions into next week could produce significant slab and loose snow avalanches. When planning for the weekend, consider that this is one of the times when an ‘improbable’ avalanche might actually occur.

If you're out in the snow, share your observations with us and your local backcountry community.

Regioni coperte