Regions
Northwest Inland.
Confidence
Fair - Due to the number of field observations
Weather Forecast
A series of frontal systems will be sending waves of light precipitation amounts accompanied by strong southwesterly winds. Model runs are in agreement with timing and precipitation amounts.Sunday night: Snow amounts 5 cm. Ridgetop winds blowing strong from the SW gusting strong. Monday: Snow amounts 5-10 cm. Alpine temperatures -5.0. Moderate SW ridgetop winds with strong gusts. Tuesday: Snow amounts 5-10 cm. Alpine temperatures near -6.0. Ridgetop winds moderate from the SW.Wednesday: Trace. Alpine temperatures near -7.0 with light SW ridgetop winds.
Avalanche Summary
No new avalanche activity has been reported. Reports from the Coastal region have seen natural slab avalanches up to size 2, additionally some larger size 2.5 were triggered with explosives control. Numerous size 1-2 skier remote (up to 50 m away) slab avalanches released down 60 cm all on the old buried surfaces mentioned above in the snowpack summary. A poor bond exits with the new snow and old surfaces; however I think the Inland region lacks the snow amounts to be as reactive as the Coastal region. I would be suspicious of wind loaded slopes at all elevations, use conservative terrain choices and make observations as you travel.
Snowpack Summary
The region has received between 30-55 cm of new snow which overlies a variety of old surfaces. These buried surfaces consist of weak surface facets, surface hoar (more predominant at treeline and below treeline elevations), a scoured crust, wind press, or any combination of these. Whumpfing, cracking and reports from the field indicate a very poor bond between the new snow and these old surfaces. Strong winds and slight warming may have added cohesion to the new storm slab, and have shifted the new snow into deeper, and potentially destructive wind slabs in exposed terrain.The mid and lower snowpack are generally strong and well-settled. Basal facets and depth hoar are likely to exist in some parts of the region, but triggering has become unlikely.
Problems
Wind Slabs
Wind Slab avalanches are the 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.