Avalanche Forecast
Regions: Olympics.
Very dangerous avalanche conditions are expected to develop especially near and above treeline Friday due to an incoming storm system. Travel in avalanche terrain is not recommended due to the increasing hazard.
Detailed Forecast
Several waves of warm frontal moisture will impact the Olympics Thursday night through mid-day Friday. A strong cold front will sweep through the area early in the afternoon. The warming trend should peak early afternoon for the Olympics. Â
Rain will creep higher in the below treeline band late Thursday night through Friday morning for the Olympics before snow levels begin to fall in the afternoon. Moderate to strong southwest winds will increase Thursday night and stay elevated through Friday afternoon.  Â
Very dangerous avalanche conditions are expected to develop especially near and above treeline Friday due to an incoming storm system. Travel in avalanche terrain is not recommended due to the increasing hazard.Â
Storm slab should build and become more reactive late Thursday night through mid-day Friday day due to the warming trend. Â
Wind slab will build on lee easterly aspects near and above treeline, but expect cross-loading and wind slab formation into the upper portion of the below treeline band due to the strength and duration of the winds. Â
Generally shallow loose wet avalanches are likely below treeline.Â
Snowpack Discussion
Weather and Snowpack
The most recent wet warm storm arrived on Valentines Day 2/14 and formed the uppermost, very strong rain crust in the snowpack.Â
A series of disturbances in cool, NW flow aloft from Saturday through Tuesday caused periods of moderate to strong S-SW-W alpine winds at Hurricane. The 4 day storm snow amounts over this period were about 10 inches at Hurricane Ridge.
The NPS ranger at Hurricane Ridge reported 4 inches of new snow Thursday morning with south winds increasing to 10 to 20 mph.Â
Recent Observations
No observations have been received from the Olympics in the past several days.
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, North West.
Elevations: Alpine, Treeline.
Likelihood: Very 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
Loose Wet
Release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. They generally move slowly, but can contain enough mass to cause significant damage to trees, cars or buildings. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Travel when the snow surface is colder and stronger. Plan your trips to avoid crossing on or under very steep slopes in the afternoon. Move to colder, shadier slopes once the snow surface turns slushly. Avoid steep, sunlit slopes above terrain traps, cliffs areas and long sustained steep pitches.
Several loose wet avalanches, and lots of pinwheels and roller balls.
Loose wet avalanches occur where water is running through the snowpack, and release at or below the trigger point. Avoid terrain traps such as cliffs, gullies, or tree wells. Exit avalanche terrain when you see pinwheels, roller balls, a slushy surface, or during rain-on-snow events.
Elevations: Below Treeline.
Likelihood: Likely
Expected Size: 1 - 1