Weather Forecast
Temperatures should drop down to about -12.0 in the alpine by Wednesday morning. The ridge of high pressure is expected to continue to bring clear skies and light winds during the day Wednesday. Alpine temperatures may rise above freezing on solar aspects, but should remain slightly below freezing on shaded aspects. Cloud should move into the region overnight and precipitation is expected to begin by about noon on Thursday. Western parts of the region may get 5 cm combined with moderate southerly winds. The freezing level should rise to 900 metres during the day and drop back to near valley bottom overnight. Another ridge is forecast for Friday that should bring mostly clear skies and light winds during the day.
Avalanche Summary
One size 2.5 natural dry slab avalanche was reported on a SE aspect at about 2400 metres elevation.
Snowpack Summary
The new snow layer above the February 09 surface hoar is now about 10-15 cm thick. There has been very little wind during the recent flurries. Some areas have reported that the surface hoar had grown to 50 mm before being buried. Some thin windslabs have developed due to down flowing air on large glaciated features. A melt-freeze crust has developed on solar aspects at all elevations, and on all aspects below about 1400 metres. The mid-pack is generally well settled. There is some concern that large loads like cornices may trigger the Jan. 20th facet layer. Some shallow snowpack areas may continue to have a weak layer of basal facets near the ground.
Problems
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.