Avalanche forecast

West Slopes Central

Northwest Avalanche Center
View on map

Avalanche danger

Mon
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
Open full map
Out of date — this forecast expired 4 years ago. You’re viewing past conditions, not the current bulletin.

Highlights

Rising temperatures - nearing 50F at 5000' - will perpetuate the pattern of sporadic wet avalanche activity. Reduce your exposure to cornices and very steep terrain overhead, especially on northerly aspects near and above treeline. 

Avalanche problems

  • Loose Wet

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

    We will continue to see occasional wet loose and slab avalanches until there is a sustained drop in temperature. A few cornices have fallen so far and many are sagging and looking unstable after a week of mild temperatures. Glide avalanches where the entire snowpack slides on a smooth ground surface (i.e. rock slab) are also possible. Though most avalanches in the last week were “naturals” it’s still possible for a person to trigger a wet loose in very steep terrain holding saturated, unconsolidated snow. Cornices could also fail under the weight of a person or snowmobile. 

    The easiest way to reduce risk is to simply avoid traveling on or directly under very steep, slopes, especially during rainfall or periods of sun. The same advice holds true when the snow surface is wet and unsupportable. Give cornices, glide cracks, and steep, rocky areas still holding snow a wide berth as well. Avalanche activity is less likely when a thick, melt-freeze crust is present at the snow surface.

    (3/22/2022) Large wet loose avalanches off the SE side of Lichtenberg. Photo: Matt Primomo

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely
    Size
    3

    A layer of weak, faceted snow buried on March 8th was the root cause of a very, very large natural avalanche that occurred on Wednesday morning - in addition to three others the previous week. This large slab avalanche might also have run on the layer in question. There is a slim chance you could trigger one of these monsters as the layer in question is buried around 4-6’ deep. The greater concern is that one releases in alpine terrain above you triggered by cornice fall, a smaller wet snow avalanche, or for some other reason. Though all known avalanches of this type initiated near or above 5500', some traveled far down into treeline. 

    As with the wet avalanche concerns listed above, there isn’t really much you can do to outmaneuver this problem. You are either in the terrain where one of these avalanches might occur, or you are not. If you choose to travel in these areas your a simply accepting a slightly higher risk of triggering or being exposed to this problem. 

    (3/23/2022) A very large natural avalanche which occurred early Wednesday morning on the Shuksan Arm. Possibly up to a 5' crown. Photo: Kris Stemmler

Avalanche Discussion

Look for freshly wind loaded features and shallow slabs anywhere it was cold enough for dry snow to accumulate. This is most likely on the highest peaks and heading east towards the Cascade Crest.

On Saturday few inches of new snow near treeline reportedly did little to influence avalanche danger. The biggest upshot was a period of cold temperatures that reduced the likelihood of a larger avalanche or cornice fall. Dry new snow was noted above treeline but will quickly fall victim to 6000-7000’ freezing levels Sunday.

Despite a lack of reported avalanche activity in the last 48 hours, the current snowpack is still wet, weak and generally unstable and manky. Periods of colder temperatures have limited avalanche danger and created a boot supportable crust the last few days with quasi corn conditions at mid and upper elevations. Though the bulk of wet loose avalanche activity has run its course, overhead hazard with the “spring shed” continues. Plenty of avalanche terrain presents low risk, but it can be difficult to predict which slopes will or won’t produce avalanches or other hazards until the mountains get a good freeze and stop slowly falling apart.

Avalanche, snowpack, and weather conditions vary quite a bit between zones to the north, east, and south of West Central.  Greater quantities of new snow to the north have made for an extended period of wet avalanche activity given the current mild temperatures. In addition, large avalanches releasing in a faceted layer have occurred to the north while Stevens or Snoqualmie Passes have seen no avalanches of this type. With limited observations in West Central refer to forecasts for Stevens or Snoqualmie Passes if traveling in terrain adjacent to those zones

 

Regions covered