Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Sun
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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Non aggiornato — questo bollettino è scaduto 6 years ago. Stai vedendo condizioni passate, non il bollettino in corso.

In sintesi

Conditions may be variable across the zone on Saturday, requiring you to do some pre-trip homework and to take frequent observations as you travel. If you find yourself above the rain/snow line, be prepared for the possibility of avalanches due to wind and snow. If you find yourself in the lowlands, you could find lower avalanche hazard with early season travel conditions.

Problemi valanghivi

  • Wind Slabs

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

    The wind has continued to blow in the alpine and on the volcanoes, with fresh wind loading at middle and upper elevations observed at Paradise on Friday by NWAC team members. With a quick shot of snow and some moderate winds set to impact the zone on Friday night, we’ll keep Wind Slab as our primary focus for Saturday. Look for these slabs on leeward slopes, at the base of cliffs, or on the sides of gullies in any part of the zone that receives more than a few inches of new snow. Taking note of freshly built cornices, textured snow surfaces, or pillow-like piles of snow could help you determine where these slabs may exist. You can then use small inconsequential slopes to test the bonding to the old snow surface and the sensitivity of any potential slab. If you find reactive pockets of snow or a poor bond, think twice before stepping into consequential terrain.

    (11/27/2020) Blowing snow, Rime on the trees and cliffs, or pillow-like piles of snow are good visual clues for Wind Slabs. All three of these signs were visible on Friday in the Paradise area.

Avalanche Discussion

Friday, NWAC staff reported multiple Wet Loose avalanches at middle and lower elevations at Mt. Rainier, while also noting active wind transport at middle and upper elevations. This week’s snow was found to be fairly well bonded to the old snow surface, but a small mid-storm layer about 1” above the 11/24 interface was found to have a possibility of failure. As we move into the weekend with precipitation in the forecast, keep this interface in mind. Depending on where you find yourself in the West South, conditions may look a little different on Saturday. At lower elevations, you could find that rain has fallen overnight and avalanche hazard may be minimal but traveling conditions are hazardous due to open creeks, exposed rocks, and stumps. As you ascend in elevation above the rain/snow line, avalanche hazard may be more pronounced with fresh snow which has been drifted into deeper and more reactive piles. In some parts of the zone, you may find that little precipitation has fallen, creating a locally lower avalanche hazard. Take some time to do some homework before you leave home about how the weather impacted the area you hope to visit. Then take that information and combine it with observations you take while traveling to create your own hazard assessment for the day.

During the ongoing Covid-19 pandemic, continue to follow the latest guidance from local, state, and federal health officials. Avoid unnecessary risks that could impact first responders and stress medical resources.  Wear a mask when appropriate, practice social distancing, and consider recreating closer to home.

Regioni coperte