Avalanche Forecast
Regions: Olympics.
Tuesday should be another wet day at Hurricane, with periods of heavy precipitation. Careful snow evaluation and cautious route finding should be essential if you venture into avalanche terrain.
Detailed Forecast
Another strong warm front should cause renewed strong southwest to west winds and periods of moderate to heavy rain or snow Tuesday along with further warming.Â
New wind and storm slab will again be the focus on Tuesday at Hurricane Ridge where snow should change to rain. Careful snow evaluation and cautious route finding should be essential if you venture above treeline.
With little snow near and especially below treeline at Hurricane, wet loose snow avalanches will not be in the forecast. But change your plans if you find wet snow deeper than a few inches or see signs of wet loose activity such as pin wheels or natural wet loose avalanches.
Snowpack Discussion
We have not received any snowpack observations from Hurricane Ridge so far this season. However, given the warming and heavy precipitation over the past few days, and especially the significant warming, wind and precipitation Monday, it is very likely that an unstable upper snowpack has developed over the Olympic Mountains. Heavy dense recent snow likely overlies a strong melt-freeze crust from mid-November. This likely snowpack structure should have formed dangerous avalanche conditions above treeline where extra caution is essential.Â
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.
Likelihood: Likely
Expected Size: 1 - 1
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.
Likelihood: Possible
Expected Size: 1 - 1