Bollettino valanghe

East Slopes South

Northwest Avalanche Center
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Pericolo valanghe

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

In sintesi

You may be able to trigger an avalanche at upper elevations where winds formed shallow slabs. Look for drifts of snow below ridges and steer around them steeper terrain. Saturday will be the warm-up for a more significant storm overnight, so expect increasing danger in the late afternoon hours. 

Problemi valanghivi

  • Wind Slabs

    • Alta quota
    • Limite del bosco
    • Sotto il limite del bosco
    Probabilità
    Possible
    Dimensione
    1

    You could trigger small avalanches in new or lingering wind slabs on Saturday. But the fresh slabs are likely more sensitive and easier to trigger. Look for actively blowing snow, drifts, and cornice formations to point you toward wind-loaded areas. If you observe shooting cracks or the snow feels stiff and hollow, simply steer around steep terrain to avoid triggering an avalanche. With minimal snow totals, these avalanches likely won't be large. But don't be caught off guard in steep, consequential terrain where a fall could have high consequences, particularly with the low snow cover. Even a small avalanche could be a rough ride over exposed rocks and other hazards. 

    An illustration of early-season wind loading and the textures and patterns that point to wind slab locations. 

Avalanche Discussion

With the last rain event behind us, a smaller but significant atmospheric river will impact the Cascades late Saturday into Sunday. The east slopes of the Cascades may see around 1ft of new snow, with the highest snow totals near the Cascade Crest. 

Thankfully, we put the saturated snowpack in the freezer on Thursday night, with temperatures well below freezing at all but the lowest elevation weather stations. While we don't know the full impacts of the prolonged rain event on the snowpack yet, especially at upper elevations, there's a good chance that the November weak layers changed to meltforms on most slopes. We know that all but the highest peaks now have a stout melt-freeze crust on the surface. Mission Ridge Patrol reported the crust to be nearly 8" thick in the adjacent East Central zone. While this next round of snow will fall on a much stronger snowpack base, we must wait to see how well it bonds to the newly formed crust. 

Unfortunately, with last week's rain and warm temperatures, many areas lost over 50% of their snowpack. Lower elevations have a lot of exposed bare ground, so depending on where you go, the chance to hit buried rocks, logs, and other obstacles may still be a significant hazard. The refrozen snowpack may also make travel challenging, so ensure you have suitable equipment, such as scratchers on your snowmobile, crampons, or ice axes to travel on steep icy slopes.

We don't have much for on-the-ground observations of East South. So, if you're out enjoying the new snow, let us know what you see by submitting an observation.

Regioni coperte