Avalanche forecast

East Slopes Central

Northwest Avalanche Center
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Avalanche danger

Fri
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

The avalanche danger is slowly easing as temperatures cool. The risk of wet avalanches remains a concern where the snow is wet and unsupportive, especially on steep rock slabs and unsupported slopes. Cold wintery conditions return to upper elevations, where you may find shallow drifts of snow on leeward slopes.

Avalanche problems

  • Wet Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    A lingering chance for wet avalanches is maintaining moderate danger. While they're becoming less likely, the consequences are worth keeping in mind. Wet slabs could be large and could entrain mud as they flow downhill. Avalanches may encompass a variety of all things wet, including wet loose, glide slabs, and debris flows.  Glide slabs can release a large area of snow from overhead rock slabs or grassy slopes. If you find yourself sinking deep into wet, unconsolidated snow, don't go onto or linger underneath steep slopes and large features. 

    Upper elevations may be less of a concern for wet avalanches on Thursday as they begin to freeze. See more below.  The snowpack is very shallow in much of the zone below ~4,500ft. The lowest elevation slopes are too bare for winter travel or avalanche hazards.

    (12/6/2023)

    A small wet slab that likely ran on Dec 4-5th in the Salmon LaSac area. This may have been triggered by a cornice fall from above. 

    Photo: Katie Warren

Avalanche Discussion

A deluge of rain started around December 3rd. You can expect precipitation to slow and cooling temperatures as we close in on the weekend. We know that a widespread cycle of wet avalanches occurred, though we're still tallying the extent of the cycle. The other impacts of the rain, while discouraging to winter recreation, have been impressive. On Wednesday, Katie Warren went to the Salmon La Sac area and found a well-saturated snowpack. Even low in the drainage, she found over a foot of wet snow at 4,800ft. Evidence of flooding was clear. Similarly, Josh Hirshberg found high water and a shallow, wet snowpack in the Icicle Creek drainage. Summer roads have just enough snow to slide on, as you approach the Cascade Crest.

Prior to the rain, observers reported many signs of instability across the region. On Sunday, the Mission Ridge Pro Patrol reported propagating slabs and touchy conditions. These slabs generally failed 6-12 in deep and upwards of 2 ft in wind-loaded areas. Observers in neighboring zones have reported widespread avalanches, failing on faceted snow from November. While we don't know the full impacts on the snowpack, especially at upper elevations, there's a good chance that the November weak layers have changed to meltforms on most slopes. Before this week's storm, snow cover was minimal to nonexistent below 4,500ft, especially on sun-exposed slopes. Depending on where you go, the chance to hit buried rocks, logs, and other obstacles may still prove a significant hazard. 

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