Regions
Northwest Inland.
Avalanche hazard will likely be on the rise Wednesday as new snow and wind add fuel to the existing wind slab problem.
Confidence
Poor - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Wednesday: 2 to 10cm of snow expected above 1300m. Light SE winds at treeline, Strong SW winds at ridgetop.Thursday: Trace of snow. Moderate SW winds at treeline, strong SW winds at ridgetop. Freezing level holding at 1500m.Friday: Freezing level fluctuating between 1000m and 1500m. 1 to 5cm of snow possible. Moderate SW winds at treeline, strong SW winds at ridgetop.
Avalanche Summary
Numerous size 1 loose wet avalanches were reported on Saturday. They failed in steep rocky terrain in response to warming and solar radiation. On Sunday cornice failures to size 2 were reported. Several small wind slabs from immediately lee of ridge crest were reported Monday.
Snowpack Summary
Light accumulations from Friday may now exist as a soft wind slab in high elevation lee terrain. The new snow overlies older wind slabs, crusts and wind-scoured surfaces. Sun-exposed slopes and lower elevation areas are likely in a spring melt-freeze cycle. Weaknesses buried in the upper snowpack may include hard crusts and/or facet crystals, although not much is known about the reactivity or spatial distribution of this layer. At the base of the snowpack, weak facets may be found. Cornices are large and potentially fragile.
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.