Avalanche Forecast
Regions: Olympics.
New snow may initially bond poorly to a variety of snow surfaces Wednesday. Travel conservatively and expect a rising avalanche hazard throughout the day.
Detailed Forecast
New storm and wind slab should build during the day on Wednesday as a Pacific frontal system approaches from the west.Â
Storm slabs should be shallow but should become increasingly sensitive due to a warming trend during the day. S-SW transport winds will build wind slabs on lee aspects. Watch for signs of cracking or firmer wind transported snow.Â
New snow may initially bond poorly to a variety of snow surfaces Wednesday. Travel conservatively and expect a rising avalanche hazard throughout the day.Â
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Snowpack Discussion
Heavy rain fell in the Olympics last Wednesday and Thursday (1/27-1/28) with over 2 inches recorded of rain at the Hurricane Ridge NWAC station.Â
The "20th of June" path released as a wet slab during rain and warmth last Thursday. Photo taken January 29th by Matt Schonwald.
A strong front last Friday brought 14 inches of new snow for the 2 days ending Saturday morning. This storm snow has accumulated on top of the most recent rain crust.
NWAC pro-observer Matt Schonwald visited Hurricane on Friday January 29th and found rapidly building wind slab and extensive loading on lee slopes in all 3 elevation bands. New cornices were sensitive to triggering but still relatively small.Â
No new observations have been received since Friday. Cool weather with some light snow showers occurred over the Olympics Sunday and Monday while Tuesday was cool and partly sunny. The recent weather should have promoted stabilization of the most recent storm snow above the rain crust.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: 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: Likely
Expected Size: 1 - 1