Avalanche Forecast
Regions: Cascades - South West.
A low danger is expected on Thursday. Watch for terrain hazards due to the low snowpack.
Detailed Forecast
Partly cloudy weather with a slight chance of a few light rain showers should be seen this evening to Thursday morning. Most areas will see no precipitation. Decreasing clouds should be seen Thursday afternoon and night. Winds will be light with a slow warming trend.
This weather will cause little change in snow conditions and an overall low danger.
The limited avalanche problem to watch for should be loose wet avalanches. Watch for wet snow deeper than a few inches on steep solar slopes. But the likelihood and size will be listed as unlikely and small respectively.
Due to the low snowpack at lower elevations watch for terrain hazards such as open creeks, partially covered rocks and vegetation.
Snowpack Discussion
Last weekend a warm front caused high snow levels and rain. Most NWAC sites west of the crest had about 1-3 inches of rain. This caused loose wet avalanches, some possible wet slab avalanches and consolidation. West of the crest a lot of water was seen in and draining from the snow pack.
More mild and some sunny weather was seen Sunday to today.
Pro-observer Jeremy Allyn was at Nason Ridge at Stevens Pass on Sunday and found the January 15th facet/crust interface under a settled and moist to wet 45 cm of snow. While this layer gave a CTH RP at a density change below the crust it seemed unlikely to propagate. With this mild weather the facets will be rounding and the interface should be strengthening and stabilizing.
NWAC forecaster Dennis D'Amico found previous loose wet avalanches on Monday on this SE aspect at about 6500 feet in the Paradise Glacier Valley, possibly triggered by small cornice drops during the weekend rain event. Here are a couple of his photos.
The snowpack in most areas west of the crest should consist of stable consolidated rounded grains or melt forms and crusts from multiple warm periods this winter.
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: South East, South, South West.
Elevations: All elevations.
Likelihood: Unlikely
Expected Size: 1 - 1