Regions
Northwest Coastal.
Confidence
Fair - Due to variable snowpack conditions
Weather Forecast
Monday: Freezing Level: 500m Wind: Mod S/SW, No significant precip.Tuesday: Freezing Level: 500m rising to 750m, Wind: Light W, No significant precip.Wednesday: Freezing Level: 500m Wind: SW, initially moderate increasing to strong by sundown. 10cm of snow expected.
Avalanche Summary
Improved visibility on Saturday revealed the extent of a large natural avalanche cycle in the North. The big winds and large snowfall drove a cycle to size 3.5. Observations in the southern half of the region were much smaller with cornice failures resulting in size 2 avalanches. The sun is really gaining strength as we get closer to the Spring Equinox which is driving ongoing point releases on solar aspects.
Snowpack Summary
The latest storm continued through Friday evening which brought 70cm of relatively warm snow to the Northern half of the region. Southern storm totals average around 20cm. The storm was accompanied by moderate winds that were initially out of the SW switching to NW during the later half of the storm. The winds left a mix of wind damaged snow in both the alpine and treeline elevation bands. Slab properties vary from upside down soft slab to stiff and deep wind slab. With all the new snow and wind I imagine that there is quite a bit of cornice development in the region too.The mid and lower snowpack layers are generally well settled.
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.