Avalanche Forecast
Regions: Olympics.
While recent storm related avalanche problems will have greatly diminished by Saturday, isolated areas of wind slab may remain on lee N through SE slopes near and above treeline. Also, loose wet avalanches will be likely on steeper solar slopes, especially during prolonged periods of sunshine.
Detailed Forecast
Variable cloud cover on Saturday will be accompanied by generally light winds and rising freezing levels. An incoming frontal system arriving Saturday night should spread high clouds over the area in the afternoon.Â
Recent storm related avalanche problems will have greatly diminished by Saturday. Isolated areas of wind slab may remain on lee N through SE slopes near and above treeline, but should generally be stubborn to human triggering. Firm wind transported snow and snowpack cracking can be good signs of wind slab layers.
Loose wet avalanches will be likely on steeper solar slopes, especially during prolonged periods of sunshine. Be aware of terrain traps where even a small loose avalanche could have unintended consequences in the wrong terrain.   Â
Although stubborn to trigger, some recently formed cornices have grown large. If traveling along ridgelines, be aware that cornices break much further back than expected and you don't want to go for a ride with a chunk of cornice. Despite the recent cool weather, cornice releases can be unpredictable during the spring.
Snowpack Discussion
Weather and Snowpack
A low pressure system crossed the Northwest on Monday and Tuesday. NWAC stations along the west slopes and Hurricane Ridge accumulated a few inches above 4000 feet during this time. Light rain was seen on Wednesday in the below treeline band before a cold front swept through Wednesday night. About 4-6 inches of snow accumulated above 3500 feet Wednesday night through Friday morning, with new snow of over a foot on wind loaded slopes near treeline. Â
Frequent March storms have built large cornices along some ridges in the Hurricane Ridge area.
The mid and lower snowpack in the Olympics should generally be a stable mix of crusts and layers of moist and rounded snow crystals.
Recent Observations
NWAC professional observer Matt Schonwald toured in the Hurricane Ridge area Friday 3/25.  Matt generally found the new storm snow unreactive in snowpit tests and with ski cuts on test slopes. No recent avalanches were observed in the Hurricane Ridge area. Wind effects were limited to directly below ridgelines, with generally settled powder and good skiing found on non-solar aspects with less wind effect. Area cornices were firm and unlikely to trigger.Â
Hurricane Weather Station
Internet communications were restored to the station on 3/23! Â Thank you for your patience.Â
Avalanche Problems
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.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
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, Treeline.
Likelihood: Unlikely
Expected Size: 1 - 1