Avalanche Forecast
Regions: Olympics.
Play it conservative on Monday and give new wind slabs time to settle by avoiding freshly loaded slopes. Wind slab may extend into the below treeline zone as strong winds Sunday and Sunday night transported snow further downslope than usual.
Detailed Forecast
Showers and at times blustery southwest winds Sunday night should quickly ease Monday morning. High clouds from an approaching warm front will spread over the Olympics mid-day. Snow levels will remain relatively cool.Â
New wind slab should be sensitive on lee aspects Monday, with significant amounts of new snow transported Sunday and Sunday night. Play it conservative on Monday and give new wind slabs time to settle by avoiding freshly loaded slopes. Wind slab may extend into the below treeline zone as strong winds Sunday and Sunday night transported snow further downslope than usual. Watch for firmer wind transported snow and surface snow cracking as you travel throughout the terrain.
The storm system came in right side up with a cooling trend, so storm slabs will be a lower concern and possible in non-wind affected terrain.Â
Snowpack Discussion
Weather and Snowpack
Springlike weather under high pressure Wednesday and Thursday led to abundant sunshine with temperatures climbing into the 40's. This weather allowed for melt-freeze crust formation and varying amounts of wet surface snow depending on slope aspect during the day. A weak front brought mostly light rain to Hurricane Friday night to Saturday morning.
A strong Pacific frontal system blew through the Olympics mid-morning Sunday. Around 8 inches of snow accumulated through Sunday afternoon at Hurricane Ridge with moderate S-SW transport winds.
The mid and lower snow pack along the west slopes should generally be a stable mix of crusts and layers of moist and rounded snow crystals.
Recent Observations
NWAC pro-observer Matt Schonwald was at Hurricane Ridge Friday and found mostly consolidated stable snow. N to E slopes had areas of 25-30 cm of wind transported 4F snow well bonded to 1F melt form grains in the upper snow pack. South through west slopes were melted out in some places with shallower dense stable snow in others.
The road to Hurricane Ridge remained closed on Sunday due to the weather.Â
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: North, North East, East, North West.
Elevations: All elevations.
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.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 1