Caution on shady aspects in the alpine and tree line elevation bands where a persistent weak layer may be reactive.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain on Friday
Weather Forecast
FRIDAY: Mix of sun, cloud and isolated flurries / Moderate northwest wind / Alpine temperature -4 / Freezing level 1400m SATURDAY: Cloudy with sunny periods / Light southeast wind / Alpine temperature -3 / Freezing level 1500m SUNDAY: Cloudy with scattered flurries / Moderate west wind / Alpine temperature 5 / Freezing level 900m
Avalanche Summary
On Tuesday there was a size 1 avalanche that sympathetically triggered a size 3 persistent slab avalanche resulting in a full burial. This was on a northeast aspect at 2000m, 50cm deep. Additionally there were reports of natural persistent slab avalanches size 2.5-3 on southeast through northeast aspects between 1800 and 2000m. These were reported to have happened in the previous 24-48 hours. On Monday reports show explosives and skier controlled triggered storm and wind slab avalanches to size 1.5 on north and east aspects in the alpine. On Sunday there was a report of a skier-triggered cornice failure (size 2) on a northwest aspect at 2100 m, as well as skier and sledder triggered storm slabs (size 1.5) on east and north aspects in the alpine.
Snowpack Summary
Last week's storm snow has been redistributed by moderate to strong southwest winds. This snow rests on the March 21st interface, a mix of moist grains at low elevations, crusts on solar aspects at all elevations and surface hoar/facets on north/east facing features at treeline and alpine elevations. Some west facing features may have surface hoar on top of a crust. Deeper in the snowpack, 80 to 140 cm below the surface is a combination of facets, surface hoar, and/or crust known as the mid-February layer. This interface has not been active recently.The mid and lower snowpack are strong and well settled.
mbender,
Avalanche Canada
