Avalanche Forecast
Regions: Olympics.
The avalanche danger will be increasing Wednedsay. Unstable wind and storm slabs should be widespread. Cautious routefinding and conservative decision-making is essential. Avoid steep terrain where wind deposited snow is evident.
Detailed Forecast
An approaching disturbance should bring renewed light to moderate snow showers at low snow levels with strong ridgetop winds overnight Tuesday and early Wednesday.
This should build new unstable wind slabs in exposed terrain, near and above treeline and some isolated features below treeline. Wind slabs should build on primarily on NE-SEÂ facing slopes, but may build on a variety of terrain features.
Storm slabs may become increasingly sensitive to human trigger, especially in areas receiving the greatest snowfall amounts Wednesday.
Expect dangerous avalanche conditions near and above treeline Wednesday. Evaluate the snow and terrain carefully Wednesday.Â
Give cornices a wide berth when traveling along ridgelines and avoid lingering on slopes below cornices as they may fail at any time.
Snowpack Discussion
Weather and Snowpack
Heavy rain to high elevations arrived on Valentines Day 2/14 and subsequently formed the uppermost, very strong rain crust within the snowpack.Â
Cool NW flow over the past two weeks brought several disturbances across the region. Mostly with very cool temperatures and light winds. The storm snow amounts in the Hurricane Ridge area, has been about 15-20 inches following the rain crust, producing event on Valentines.
 NPS Rangers reported that the most recent rain crust was very supportable in many areas and aspects around Hurricane Ridge.
Older wind slabs have stabilized while generally 10-15 inches of low cohesion snow over the crust, have made for some nice touring conditions of late.Â
Recent Observations
No observations have been received from the Olympics in the past several days.
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, South East, North West.
Elevations: Alpine, Treeline.
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