Avalanche Forecast
Regions: Cascades - South East.
Be aware of slightly greater avalanche danger in steeper terrain and near terrain traps relating to wet avalanches. The avalanche danger will be lower at lower elevations and away from the Cascade crest due to low snow conditions.
Detailed Forecast
Cooler temperatures with clouds and a few light showers are expected Tuesday. Only very light amounts of precipitation are expected, if any, and this should not change the overall low danger.
Generally avoid steep slopes, especially near terrain traps where you might be able to push off enough wet snow to start an avalanche large enough to take you for a ride.
Remember, due to the unseasonably low snowpack especially at lower elevations, numerous terrain hazards such as open creeks, partially covered rocks and vegetation are widespread. Â
Snowpack Discussion
Snow on the back end of the last winter storm one week ago was in the 6-24 inch range east of the crest with the most significant snow recorded at Holden, Washington Pass and due east of Stevens Pass.
The warm and wet system that affected the PNW Thursday through Saturday did push high freezing levels over to the east slopes, but brought drastically lower rainfall totals than the west side; generally less than 1 inch of rain was received for the previous 48 hr ending 4 am Sat along the east slopes. This likely did not thoroughly test the most recent storm snow and various weak layers in the upper snowpack although the warm temperatures have promoted rounding in the upper snowpack. Â
Recent Observations:
NWAC pro-observer Tom Curtis was at Mt Cashmere on Friday and at 5600 ft found 30 cm of recent wet snow on old facets that were turning to rounded grains on the Jan 15th crust. Compression tests gave sudden collapse and sudden planar results, but was not likely to propagate. On Sunday, Tom was in the Jove Pk area east of Stevens. The Jan 15th facet/crust combo was buried at least 1 m on lee northerly aspects near treeline and un-reactive in tests. However, on a SE aspect near-treeline, the PWL was 50 cm down and produced sudden collapses in compression tests. While no natural or human triggered avalanches were observed, this is still a layer to watch. Â
In the same central-East zone further away from the crest, Mission Ridge pro-patrollers reported depth hoar rounding, but still reactive in snowpit tests (failing on isolation in a full 60 cm pit) on a lee east aspect near treeline. While snow cover in the Blewett/Mission Ridge area is spotty and thin, persistent weak layers still exist from earlier this winter. 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.
Elevations: Treeline, Below Treeline.
Likelihood: Unlikely
Expected Size: 1 - 1