Avalanche Forecast

Moderate - Due to the number of field observations

Monday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light to moderate from the southwest. Freezing level around 400 metres with alpine temperatures of -11 in the north of the region, closer to -7 in the south. Tuesday: Mainly cloudy with flurries bringing 5-10 cm of new snow, beginning in the afternoon. Winds moderate to strong from the southwest. Freezing level to 700 metres with alpine temperatures of -8 in the north of the region, closer to -5 in the south. Wednesday: Mainly cloudy with scattered flurries bringing around 5 cm of new snow. Winds strong to extreme from the southwest. Freezing level to 700 metres with alpine temperatures of -10 in the north of the region, closer to -7 in the south.

Reports from Saturday include one observation of a natural wind slab (size unknown, likely 1-2) releasing naturally on a northeast aspect in the Duffey Lake area in direct response to wind loading from the southwest. A social media report from Thursday showed a persistent slab release to approximately Size 3 in the Hurley area. The slab was triggered with a cornice cut on an apparently northeast aspect, though it should be noted that the cornice was not large. See the video here. The above report has combined with the Size 3 persistent slab avalanche observed up the Hurley last Friday to suggest the possibility of an emerging pattern of persistent slab activity in that part of the region. The failure planes of each slide remain uncertain, but the early February surface hoar layer was suspected in Friday's occurrence.While wind slabs remain an ongoing concern throughout the region (especially in the south) a low-probability/high consequence avalanche problem should be driving a more cautious approach to backcountry travel in the north of the region.

Scattered flurries delivered a variable 10-35 cm of new snow to the region over Thursday to Saturday night, with the greatest accumulations occurring in the south of the region. Recent southwest winds have been noted blowing the new snow into wind slabs in lee terrain in the north of the region, leading to easy whumphing and cracking observed at ridgetop in the Duffey Lake area on Sunday. Below the new snow, the previous snow surface consisted of surface facets and surface hoar to 6 mm, as well as sun crust on steep solar aspects. Beneath the new snow interface, 10-30 cm of recent storm snow overlies the widespread mid-February crust layer, now down roughly 20-60 cm at higher elevations. Reports suggest this storm snow is well bonded to the crust but has been undergoing faceting as a result of recent cold temperatures. In the north of the region, a facet/surface hoar layer from early February, down 60-100 cm, remains reactive in snowpack tests and is suspected as the failure plane in at least one of two recent large persistent slab avalanches in the Hurley area. In the south of the region, the mid and lower snowpack are well settled and strong.