Avalanche Forecast
Regions: Olympics.
Snow conditions and overall stability still vary a lot across the region.
Detailed Forecast
Fair weather should be seen Thursday but with continued very cold temperatures. Increasing mid or high clouds should be seen by Thursday afternoon. The cold temperatures will maintain or increase any weaknesses and layers in the snowpack.
Where the snow is less consolidated generally small loose dry avalanches will be a concern on steeper non-solar slopes.
Watch for small areas of old wind slab on previous lee slopes.
Moderate avalanche danger specifically means that natural avalanches have become unlikely but human triggered avalanches are possible in specific areas and terrain features
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Snowpack Discussion
A storm arrived at the end of January with rising snow levels and rain above 6000 feet for the Olympics before transitioning to snow and colder temperatures. Wind was less of a factor with this event with a more even distribution of storm snow and a general lack of wind slab.
Only light amounts from 1-3 inches of additional snow in showers has accumulated in early February. This has given several days for settlement and gradual stabilizing of avalanche layers.
NWAC observers Tyler and Katy Reid in the Hurricane Ridge Friday and over the weekend reported limited or minimal slab layers. New surface hoar growth up to 10 mm was observed well into the near-treeline zone (see photo below). Skiers triggered unconsolidated new snow into size 1-2 dry loose avalanches on north and west aspects. Large wet loose slides were reported around 6000 feet on the E-SE slopes of Mt. Angeles. No information has been received from the above treeline zone deeper in the Olympics.Â
Recently surface hoar with graupel from showers on 1 February at Hurricane Ridge area, N aspect @ 5200 ft by Seth Waterfall.
Regionally the avalanche danger is lower near Hurricane Ridge than in the Washington Cascades where a more diverse snowpack exists. See the Cascades forecast if traveling there.
The mid and lower snowpack west of the crest consists mainly of crusts and melt form crystal layers which have generally not been reactive to to snow pit tests. Low snow amounts are limiting the avalanche danger on many south slopes and at low elevations due to terrain and vegetation anchors.
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.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 1 - 1