Lawinenlagebericht

West Slopes Central

Northwest Avalanche Center
Auf der Karte ansehen

Lawinengefahr

Wed
Hochgebirge
4 · Gross
Waldgrenze
3 · Erheblich
Unterhalb
2 · Mässig
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Kernpunkte

A sizeable overnight avalanche cycle is expected to continue into the day Tuesday. Several inches of water Monday night will slightly taper into Tuesday but the snowpack will probably remain reactive. Avoid steep slopes at lower elevations but if you venture higher steer clear of all avalanche terrain, including lower-angle slopes beneath large avalanche paths. 

Lawinenprobleme

  • Wet Slabs

    • Hochgebirge
    • Waldgrenze
    • Unterhalb der Waldgrenze
    Wahrscheinlichkeit
    Very Likely
    Größe
    1.5–2.5

    Wet slab avalanches are spooky and unpredictable. They usually happen when least expected, and are nearly impossible to escape. Three inches of water is forecasted for Monday night, falling as rain up to 9000ft. Water will percolate down into the snowpack, and large natural wet slab avalanches will result. Peak activity will probably happen overnight but avalanches will likely continue during the day as water travels deeper into the snowpack. Larger and more reactive avalanches are expected to occur in the upper elevation band. Further down, rain began sooner and the snowpack is shallower so activity is expected to decrease as you drop in elevation.  If you venture out, keep in mind there are a lot of uncertainties around the current snowpack and how it will react to all the recent water, so exercise more caution than you normally might during your outing.

    (3/1/2022) Example photo: Several wet slab avalanche crowns visible in this photo. Avalanches will probably be larger on Tuesday. Photo: Lee Lazzara

Avalanche Discussion

You may see glide avalanche activity during this large rain event. Steep slopes with smooth underlying surfaces like rock slabs and low shrubs are culprits. If you see cracks in the snowpack, avoid traveling beneath those areas. They could exist at all elevations, including the shallow lower-elevation snowpack.  

Two to three feet of snow was present above about 4000 feet before the current weather event began Thursday 11/30. That snow was a mix of crusts, wind-packed snow, and weak facets on northerly aspects. Since then, 3 or more feet of snow has likely fallen at upper elevations. The storm started cold, with snow down to about 500ft. Temperatures have consistently warmed and will peak Monday night when the highest precipitation rates pass through with this atmospheric river. As of Monday evening, we've totaled about 5" of water in the West Central zone. We're forecasted to nearly double that amount by the end of the day Tuesday. Most avalanches will probably occur at the new snow/old snow interface, possibly in the old snow layer or even at the ground. 

Much of the snowpack is saturated and unsupportable so travel will be a challenge no matter your method of transport. It's early season and especially with an unsupportable snowpack, you'll have an easier time hitting obstacles hidden by the snow. Creeks will be flooded. Keep this in mind for your outing. 

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