Avalanche Forecast
Regions: Olympics.
The avalanche danger will continue to slowly decrease Thursday. The uncertainty will be wind transported snow near ridges and newly forming wind slabs on a variety of aspects. Watch for any wind stiffened surface snow and avoid large open slopes of consequence in higher terrain.
Detailed Forecast
Cool weather with mostly clear skies or high clouds are expected Thursday with moderate NW winds at higher elevations.Â
This weather will continue to cause a decreasing trend in the avalanche danger as recent storm snow slowly stabilizes. At higher elevations, expect wind transport and building areas of wind slab, mainly above treeline and onto unusual aspects from the mostly NNW winds.
While the overall danger is decreasing, continue to travel with caution and watch for any slab like structure or cohesion in the upper snowpack, indicating the possibility of triggered slab avalanches.  Â
Watch for touchy recently formed cornices and avoid travel on steep unsupported slopes.
Remember that beneath snow received during this storm cycle, early season terrain hazards exist, especially at lower elevations. Expect terrain hazards with poorly covered rocks, vegetation and creeks, particularly on south-facing terrain, at lower elevations, and on exposed ridges where wind events have stripped much of the season's snowcover.
Snowpack Discussion
A strong storm from late Monday through Tuesday afternoon dropped over 3 inches of water equivalent amounting to over 2 feet of new snow in the Hurricane Ridge area by early Wednesday. Strong winds with warmer initial temperatures likely built wind and storm slabs by Tuesday.
Cooling and diminishing winds with clearing through Wednesday is allowing for a slow decrease in danger as storm layers settle, especially near and below treeline.Â
The storm snow has fallen on settled old snow or crust layers formed during the long period of high pressure in early December.Â
Winds have shifted and strengthened from the north Wednesday, no doubt transporting the abundant new snow and building wind slab layers on a variety of aspects, especially near or above treeline. Â
Observations
No recent observations.
Avalanche Problems
Wind Slabs
Release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
Wind Slabs form in specific areas, and are confined to lee and cross-loaded terrain features. They can be avoided by sticking to sheltered or wind-scoured areas..
Wind Slab avalanche. Winds blew from left to right. The area above the ridge has been scoured, and the snow drifted into a wind slab on the slope below.
Wind slabs can take up to a week to stabilize. They are confined to lee and cross-loaded terrain features and can be avoided by sticking to sheltered or wind scoured areas.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Likely
Expected Size: 1 - 1
Storm Slabs
Release of a soft cohesive layer (a slab) of new snow that breaks within the storm snow or on the old snow surface. Storm-slab problems typically last between a few hours and few days. Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
You can reduce your risk from Storm Slabs by waiting a day or two after a storm before venturing into steep terrain. Storm slabs are most dangerous on slopes with terrain traps, such as timber, gullies, over cliffs, or terrain features that make it difficult for a rider to escape off the side.
Storm slabs usually stabilize within a few days, and release at or below the trigger point. They exist throughout the terrain, and can be avoided by waiting for the storm snow to stabilize.
Elevations: Treeline, Below Treeline.
Likelihood: Possible
Expected Size: 1 - 1