Avalanche Forecast

Moderate - Due to the number of field observations

Thursday night: Mainly clear with some low level cloud and light southwest winds.Friday: Sunny with cloud increasing and isolated flurries beginning in the evening. Light southwest winds, increasing to moderate in the afternoon but mainly in the south of the region. Alpine high temperatures around -1, cooler at lower elevations under a lingering mild temperature inversion.Saturday: Mainly cloudy with isolated flurries and a trace of new snow. Mainly light southwest winds, reaching to moderate in the south of the region and increasing overnight. Alpine high temperatures around -4.Sunday: Cloudy with scattered flurries bringing about 5 cm of new snow. Moderate to strong south winds. Alpine high temperatures around -2, possibly reaching to zero with a chance of an above freezing layer at around 2000 metres, especially in the north of the region.

Two recent very large (size 3) avalanches were observed in the Joffre Lakes area on Saturday. These released from the high alpine northeast and northwest faces of Mt. Joffre and Mt. Matier, respectively. The evidence of the Mt. Matier slide features several 'step downs' as the slide progressively triggered deeper layers of the snowpack, all the way down to previous summer snow cover. Both slides likely released during last week's storm. A more recent report details a similar large release from the storm on Face mountain in the Hurley Pass areaPlease submit any observations you have to the Mountain Information Network here.

Days of cool, clear weather have grown a widespread new layer of feathery surface hoar crystals on the surface. Recent sunshine has likely replaced this surface hoar with a new sun crust on steeper sun exposed aspects.Beneath the surface, the cold has also been transforming storm snow from last week into a layer of faceted (sugary) snow. This layer of storm snow increases in depth from about 5-10 cm at 1600-2000 metres, where it sits above a rain crust, to around 20 cm in the alpine above 2000 m, where the crust may not be present. Here, the storm snow is suspected to be bonding well to a settled mid snowpack.Above 2000m, alpine snowpack depths are approaching 175 cm, but recent reports suggest about half these depths around treeline in the south of the region. A crust/facet interface can be found near the ground in the alpine, but this may again be most prevalent in the north of the region. Although we have few observations of reactivity at this layer, it was a failure plane in several very large avalanches during last week's storm. It is thought that there is insufficient snow for avalanches below 1500 m, making for generally rugged travel conditions throughout the region.