Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain

FRIDAY: Flurries. Accumulation 5-10 cm. Ridge wind moderate to strong, south. Temperature -10. Freezing level valley bottom.SATURDAY: Mainly cloudy, light flurries increasing overnight. Accumulation trace.  Ridge wind moderate, southwest. Temperature -8. Freezing level valley bottom.SUNDAY: Flurries. Accumulation 5-10 cm. Ridge wind moderate to strong, southwest. Temperature -7. Freezing level valley bottom.

On Wednesday a size 2, natural cornice release was reported on a southeast aspect at 1900 m in the northern part of the region.Tuesday there was a report of a skier triggered size 1.5 soft, wind slab release (25-50 cm deep) on a northeast-facing open, treeline slope at 1900 m.On Sunday, natural wind slab activity to size 3 was reported on south / east aspects from 1250m right up to 2400m elevation. See this MIN post for a good example of these avalanches. See also this MIN post for dramatic photos of wind effect. On Saturday we received reports of a large avalanche running on a deeply buried weak layer with 1.5m crown and good propagation. This feature was steep open terrain below tree line on an east facing aspect. 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.

20-40cm of storm snow from last week is settling into a slab in the upper snowpack. Winds have been strong from the north west through south west, creating reactive hard wind slabs (10-15 cm thick) in exposed locations on down wind features. These accumulations overlie the old interface that was buried mid-February and consists of; a mix of older wind slabs in exposed higher elevation terrain, a sun crust on steep solar aspects, and surface hoar on sheltered slopes.Below the snow surface, several persistent weak layers make up a complex snowpack that still remains suspect. In the top 100-150 cm of the snowpack, two surface hoar layers buried in January can be found. Expect to find at least one of these layers on all aspects and elevations.Deeper in the snowpack (150-200 cm deep) is a facet/crust/surface hoar layer from December, most prevalent at and below tree line.Near the base of the snowpack is a crust/facet combo, most likely to be triggered from thin spots in the alpine.