Avalanche Forecast
Regions: Olympics.
Even with an overall stabilizing trend on Tuesday, dangerous avalanche conditions may persist on lee wind-loaded slopes above treeline and where storm slabs remain possible for human triggering. Evaluate the snowpack carefully and identify terrain features of concern, such as convex rollovers and slopes that may have received recent wind deposited snow.
Detailed Forecast
A weak front should pass overnight Monday, followed by light showers tapering off Tuesday morning. Another frontal system is expected late Tuesday afternoon and night. Â
New, shallow wind slab should be found mainly on lee north to east slopes near and especially above treeline. Generally avoid wind loaded slopes above treeline. Â
Older storm slabs should have mostly settled and stabilized with some new storm slabs possible. Choose lower angled slopes if you find sensitive storm layers. Â
Snowpack Discussion
Deep storm snow that fell during mid-late December is well settled, homogeneous and has stabilized so the current avalanche danger should remain confined to the uppermost recent storm snow. Fair weather over the New Year caused extensive surface hoar that was buried by a light snowfall at Hurricane January 3rd. No avalanches have been reported on this persistent layer, and an active, mild pattern over the last two weeks has likely eliminated this layer in Hurricane Ridge area.
Avalanche concerns should be limited to mainly shallow recent storm snow. Â Strom snow is settling quickly based upon the observations made by Park Rangers at Hurricane.
The latest period of snowfall has deposited about 1 foot of snow over the past three days at Hurricane Ridge, with fluctuating snow levels and periods of strong, mostly S-SW winds. 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, South East.
Elevations: Alpine, Treeline.
Likelihood: Possible
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