Extreme winds will drive the avalanche danger in many areas. The best and safest riding may be found in sheltered terrain.
Confidence
Moderate - Wind effect is extremely variable
Weather Forecast
Tuesday: 5-12cm of new snow / Extreme westerly winds / Alpine temperature of -15Wednesday: Light flurries / Moderate to strong southwest winds / Alpine temperature of -8Thursday: Light flurries / Light southerly winds / Alpine temperature of -5
Avalanche Summary
On Sunday several storm slab avalanches to size 2.5 occurred in response to new snow and wind. The avalanches failed on all aspects above 1800m. Continued wind and snowfall will promote ongoing wind slab activity. Although deeper, persistent avalanche activity has become less frequent over the past week, light triggers in shallow rocky areas, as well as large triggers such as a cornice collapse or step down from a wind slab release, still have the potential to result in large destructive avalanches.
Snowpack Summary
About 20-40 cm of new snow now covers old surfaces which include of sugary facets, a sun crust on solar aspects and surface hoar on shaded, wind-sheltered slopes. I suspect strong winds will have redistributed much of the new snow into fresh wind slabs in exposed terrain.30-60cm below the surface lies another interface, with similar character and distribution that was buried mid-February. This layer has been reactive in recent snowpack tests and is definitely worth keeping an eye on as the overlying slab gains thickness and cohesion. Within the mid and lower snowpack are several persistent weak layers that are slowly beginning to show signs of improving but still remain suspect as low probability - high consequence avalanche problems. Two surface hoar/ crust layers buried in January are now 100-150 cm below the snow surface. At least one of these layers can be found on all aspects and elevations. Deeper in the snowpack (150 - 200 cm deep) is a facet/crust/surface hoar layer buried in December. Near the base of the snowpack is a crust/facet combo layer buried in late November.
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.