Avalanche Forecast
Regions: Stevens Pass.
Steer clear of wind slabs near and above treeline, where slabs a couple of feet thick may have formed. Have a great day, but don’t let blue sky fever cloud your decision making process.
Discussion
Snow and Avalanche Discussion:
This past storm brought about 17â inches of new snow with 3.3â of water equivalent to Stevens Pass. It rained up to at least 5200ft during the storm, then a cold front with strong winds blew through as the snow accumulated. We are left with fresh, cold snow over a refreezing wet snow crust, and some deep wind drifts. During the day on the 30th, ski area snow safety teams were able to trigger wind slabs big enough to injure, bury, or kill a person with control work.
Snowpack Discussion
Coming soon
Avalanche Problems
Wind Slabs
Moderate to strong winds have created stiffer slabs at upper elevations and in wind-exposed terrain that could break widely. These slabs were often reported as being “stubborn” during the day on the 30th, still, I wouldn't trust them. Use extra caution on slopes over 35 degrees and avoid deeper drifts of snow near and above treeline.
The layer that caused the deep persistent slab problem is still there. The chances of triggering a deep slab in this area are becoming very unlikely, but still worth considering. Use extra caution especially on the eastern edge of the zone and in shallow, rocky areas near and above treeline
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: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 1
Loose Wet
New snow over a crust is a perfect recipe for loose wet avalanches, the missing ingredient is the sun. Don’t let your guard down on steep, low elevation terrain during the middle of the day. Look for signs of loose wet instability such as roller balls coming off rocky areas or trees, a moist snow surface, or other small fan shaped avalanches happening.
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: South East, South, South West.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 1