Weather Forecast
Tonight and Sunday: A weak disturbance is forecasted to bring mainly cloudy skies, a possibility of light precipitation with light N-NE winds, freezing levels at 500 m. and alpine temperatures around -10 C.Monday: A similar situation is forecasted for early Monday but should give way to a mix of sun and cloud during the day with light N winds, surface freezing levels and alpine temperatures of -10 C.Tuesday: A ridge of high pressure is gaining strength bringing more dry and cold temperatures.
Avalanche Summary
Several loose dry avalanches size 1 and 2 were reported yesterday which ran mostly from W and SW steep alpine features. A size 2 slab avalanche was also reported out of a steep rocky face which ran to ground in the basal facets.
Snowpack Summary
There is about 5 cm of light dry new snow that has buried the melt-freeze crust that developed last week. The crust has been reported to be very hard with no foot penetration on solar aspects, and variable with a 10-15 cm foot penetration on shaded North aspects. There was widespread surface hoar at and below treeline before the new snow arrived, and can be found well preserved below the thin layer of new snow. Cold alpine temperatures are facetting the near surface snow at higher elevations. Some pockets of very soft slab have developed due to wind transported new snow. Deeply buried weak layers continue to exist, yesterday’s report of a natural avalanche running to the ground on a very steep N facing slope in the alpine is a clear sign of this.
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.