Avalanche Forecast
Regions: Olympics.
New shallow storm and wind slab mainly on lee aspects may bond poorly to the existing snow surface Thursday afternoon in the near and above treeline elevation bands.
Detailed Forecast
On Thursday, an approaching weather system should bring light rain and snow at moderate snow levels during the daylight hours. Precipitation will become more intense Thursday evening.
This should minimally increase the avalanche danger in the Olympics Thursday. Shallow new storm and wind slab may develop by the end of the day near and above treeline. Loose wet avalanches seem unlikely below treeline even with rain given the consolidated state of the snowpack. Â
On backcountry travel safety note, watch for terrain hazards (exposed rocks, trees, streams, etc.) at lower elevations and on wind scoured aspects. On non-solar aspects with a slick and supportable crust, take extra caution when traversing steep slopes and be prepared to self-arrest if necessary.
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Snowpack Discussion
At Hurricane Ridge, light snow on January 4th was followed by about 2 inches of rain on Jan 5th with a warming trend. This may have caused a natural avalanche cycle. Unseasonably warm weather without any significant precipitation has continued into mid-January.
This drained, further consolidated and generally reset the entire snowpack at Hurricane. Surface melt-freeze crusts of varying thicknesses formed over stabilized rounded grain layers. On windward or southerly aspects at Hurricane there is little if any snow cover.
NWAC observer Katy Reid at Hurricane on Saturday reported areas of bare ground and a stable snowpack that only averaged 8 inches.
No avalanches have been reported in the Hurricane Ridge area for quite some time.
Avalanche Problems
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: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1