Bollettino valanghe

West Slopes South

Northwest Avalanche Center
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Pericolo valanghe

Tue
Alta quota
2 · Moderato
Limite del bosco
2 · Moderato
Sotto il limite
1 · Debole
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In sintesi

A return to more February-like weather with snow and wind is expected on Monday. This could create some avalanche problems at upper elevations, particularly in areas that receive more significant snowfall, such as the volcanoes. In areas that receive less snow, look out for firm surfaces creating difficult travel conditions.

Problemi valanghivi

  • Wind Slabs

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

    We are expecting gusty winds to accompany the incoming storm, which could result in some shallow Wind Slabs forming at mid to upper elevations. These will be more likely in locations such as the volcanoes where more snow is expected. That doesn’t mean you can’t find unstable pockets of snow in other areas, such as the crest. Regardless of your location, if you notice actively blowing snow or that some slopes are “stripped” while others are smooth and pillow-like, you’ll know that Wind Slabs could be forming on leeward slopes. Apart from near ridgelines, wind-blown snow likes to collect on the sides of gullies and confined chutes, or near the base of cliffs. If you suspect a feature to be wind-loaded, you should consider steering around it.

    (2/1/2022)

    Using visual clues can help you identify wind-loaded features to avoid.

    Photo: Andy Harrington

Avalanche Discussion

A pattern change from warm and sunny to windy, cool, and snowy is expected on Monday. The cool weather should help firm up and stabilize the current surface, creating difficult travel conditions and a good sliding surface for the incoming snow. Unlike this past weekend, the sun will not be softening surfaces as the day wears on. In many areas, early season hazards such as rocks, stumps, and creeks have risen to the surface due to the warm weather.  It will take more than this storm to fully bury them again. Take it slow and be sure you have the proper equipment and travel plan to minimize your risk of taking a long and uncontrolled fall.

Mount St. Helens and Mt. Rainier should receive the most snow and therefore larger and potentially more sensitive avalanche problems. In other areas of the zone, you could find locally lower avalanche hazard, but that doesn’t mean that hazard doesn’t exist. The new snow may not bond well to the current snow surface, so you could find that it is easily triggered and running far and fast on a firm crust. Use quick hand pits or test slopes to see how the snow is bonded and reacting to your weight. Even small avalanches have the potential to do harm if they catch you off guard on consequential slopes or involve a terrain trap.

We will continue to monitor the weak snow near the Late January Crust as a thicker slab develops above it over the coming weeks. This layer should not come into play during this storm. Above the Late January Crust, you will find settled storm snow and multiple melt-freeze crusts of varying thicknesses, including the current surface.

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