Intense winds have blown loose snow into wind slabs on all aspects and elevations. Watch for bouts of sunshine to destabilize slabs on sun-exposed slopes.
Weather Forecast
Thursday: Mainly sunny with increasing cloud over the day. Light to moderate west winds. Freezing level to 1600 metres with alpine high temperatures around -5.Friday: Cloudy with scattered flurries bringing a trace to 5 cm of new snow. Moderate to strong west winds decreasing over the day. Freezing level to 1600 metres with alpine high temperatures around -5.Saturday: A mix of sun and cloud. Light southwest winds. Freezing level to 1500 metres with alpine high temperatures around -6.
Avalanche Summary
Reports from Tuesday included one observation of a recent very large (size 3) wind slab release that appears to have stepped down to the weak layer of sugary facets at the base of the snowpack. This serves as a reminder of the potential consequences of triggering an avalanche in shallow and variable snowpack depth areas. Observations from the past couple of days have otherwise been limited by extreme winds and poor visibility. Reports from Saturday in the Castle area showed a couple of storm slabs that released to size 1.5 and 2. The smaller avalanche occurred naturally while the size 2 was explosives-triggered.
Snowpack Summary
Up to 35 cm of new snow fell in the region over last weekend. This new snow was initially redistributed by strong easterly winds before winds switched to the southwest. As a result, a mix of old and new wind slabs can now be found on a variety of aspects and at lower elevations as well.Below the wind effect, the recent snow has buried an old snow surface that consists of crusts up to 2100 metres and dry snow or surface hoar on north aspects above 2100 m. Below this layer the mid-pack is is well consolidated. Deeper in the snowpack (50-80 cm down) the surface hoar buried in mid-February is now considered dormant. At the bottom of the snowpack you'll find a combination of crusts and facets that is reportedly widespread.
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.