Avalanche Forecast

Moderate -

Saturday night: Scattered flurries bringing about 5 cm of new snow. Moderate west winds.Sunday: Mainly cloudy with isolated flurries and a trace of new snow. Moderate northwest winds. Freezing level to 1300 metres with alpine temperatures around -8.Monday: A mix of sun and cloud. Light west winds. Freezing level to 1500 metres with alpine temperatures around -6.Tuesday: Cloudy with sunny periods. Light to moderate southeast winds. Freezing level to 1800 metres with alpine temperatures around -4.

Reports from Friday included observations of numerous loose snow releases to Size 1.5 occurring with solar warming near Blue River. Improved visibility also allowed for observations of recent (up to 72 hours old) slab avalanche activity reaching up to Size 4 in the same area. The largest of these avalanches are certain to have failed on deeply buried persistent weak layers.Reports from Thursday included observations of two large (Size 2.5 and Size 3) storm slabs releasing naturally from steep alpine terrain north of Blue River. Crown fractures of these slides ranged from 60-80 cm. Extensive natural sluffing to Size 2 was also observed, with loose dry activity on northerly aspects and loose wet from solar aspects. One Size 1 cornice fall was also reported.

Up to 40 cm of recent storm snow has fallen at upper elevations. The new snow is dry up high and moist at 1800 m and below. This now brings 40-90 cm of accumulated snow which overlies a rain crust below 2000 m or a sun crust on solar aspects at higher elevations. New wind slabs are developing on leeward slopes and behind terrain features and large, fragile cornices exist along ridgelines. At higher elevations, the February weak layers are down 120-150 cm and woke up during last week's storm with many avalanches stepping down to them. The deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack and a few avalanches and cornice falls have also stepped down to these layers last week resulting in some very large full depth avalanches. These layers remain a real concern while more reactive wind slabs and cornices continue to present the risk of acting as triggers for deeper weaknesses.