Conditions can change rapidly during this time of year, especially if the sun comes out.
Be mindful that deep instabilities are present and have produced recent large avalanches.
Moderate snowfalls and high southwest winds have formed reactive storm slabs. Expect hazard to increase with elevation and to be greatest in leeward terrain.
There are indications of a destructive, persistent slab problem waking up in the Cascades. Forecasted new snow and wind will likely increase its sensitivity and destructive potential.
Surface snow may produce loose wet avalanches in steep terrain, particularly if the solar radiation is strong. Surface crust formation, where it occurs, will neutralize this problem.
No new avalanche was reported. Numerous wet loose avalanches (up to size 2.5) from the past weekend are still being observed in the area.
A few natural avalanches (size 2.5 to 3) were observed in Allison Pass this weekend. Uncertainty remains about their character (persistent or storm) but they occurred on northeast-facing slope at treeline (1740m) and had a large (200 m +) wide crown fractures.
30 to 40 cm of rapidly settling storm snow is found at treeline and above. Wind-affected snow is present in lee features. A weak layer of faceted snow or surface hoar is now buried 50 to 60 cm deep and present in higher elevations, particularly shaded terrain.
A crust from December exists buried 100 to 150 cm deep, with facets around it in shallow areas.
At lower elevations, the snow is wet, heavy and water-saturated.
Tuesday Night
Cloudy with up to 5 cm of new snow. 30 to 40 km/h southwest ridgetop wind. Treeline temperature stable around -1°C. Freezing level around 1300 m.
Wednesday
Mix of sun and clouds. 40 to 60 km/h southwest ridgetop wind. Treeline temperature stable around +6°C. Freezing level rising to 2700 m.
Thursday
5 to 10 cm of wet snow at upper elevations only. 50 to 70 km/h southwest ridgetop wind. Treeline temperature +3°C. Freezing level around 1800 m.
Friday
Mix of sun and clouds. 40 to 60 km/h southwest ridgetop wind. Treeline temperature stable around +6°C. Freezing level rising to 2700 m.
More details can be found in the Mountain Weather Forecast.
