Regions
Northwest Inland.
Strong winds have formed widespread wind slabs at upper elevations. Just how reactive these slabs are however, is a bit unknown. Be cautious in lee areas, start with small, low consequence features before working your way into bigger terrain.
Confidence
Moderate - Due to the number and quality of field observations
Weather Forecast
TONIGHT: Mostly cloudy, light flurries. Accumulation trace. Ridge wind light to moderate, southeast. Alpine temperature near -5. Freezing level 500 m.SUNDAY: Mix of sun and increasing cloud. Ridge wind moderate, southwest. Alpine temperature near -2. Freezing level 1500 m. MONDAY: Cloudy, light flurries. Accumulation trace. Ridge wind moderate to strong, southwest. Alpine temperature near -2. Freezing level 1500 m.TUESDAY: Cloudy, flurries. Accumulation 4-8 cm. Ridge wind strong to extreme southeast. Alpine temperature near -2. Freezing level 1500 m.
Avalanche Summary
A widespread natural avalanche cycle (up to size 2), triggered by intense wind loading was reported from the northern part of region on Thursday.A natural, solar triggered size 2 avalanche was reported on Wednesday morning in the Howson range, as well as skier triggered size 1 storm slab releases on a buried sun crust (30 cm deep) on a southeast aspect at 1700 m.
Snowpack Summary
From 20 cm up to 50 cm of recent storm snow is being redistributed by strong winds and sits above a variety of crusts on all but high north aspects.Weak layers buried around March 19th are roughly 40 cm below the surface (up to 100 cm in deeper snowpack areas). These weak layers include surface hoar on shaded aspects at high elevations and hard crust layers on solar aspects and below treeline.Near the bottom of the snowpack, weak and sugary facets are found in shallow, rocky snowpack areas. Storm slabs have stepped down to these facets and producing very large avalanches in northern parts of the region.
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.
Loose Wet
Loose Wet avalanches are the 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. 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.