Avalanche Forecast
Issued: Mar 24th, 2018 3:35PM
The alpine rating is Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
SUNDAY: Increasing cloud in afternoon. Ridge wind moderate to strong, southwest. Alpine temperature near -8. Freezing level 1000 m.MONDAY: Cloudy, flurries. Accumulation 2-5 cm. Ridge wind moderate to strong, southwest. Alpine temperature near -5. Freezing level 1500 m.TUESDAY: Cloudy, flurries. Accumulation 2-6 cm. Ridge wind strong, west. Alpine temperature near -2. Freezing level 1800 m.
Avalanche Summary
On Friday there were reports of isolated natural and skier triggered storm slab avalanches (size 1-1.5) from 15 to 25 deep on wind-affected convex and ridge top features in the alpine.Thursday there were reports of skier triggered size 1-1.5 wind slabs 10-30 cm deep on leeward, north-facing slopes at ridge top as well as sloughing below 1700 m in steep terrain.Last weekend, on Sunday a skier triggered avalanche was reported from around the Duffey on a north/northeast facing feature between 1900 and 2000 m. The size 2 avalanche failed on the March 8th surface hoar with a crown depth of 20 cm. And on Saturday two size 1.5 skier triggered avalanches were reported from steep northeast facing terrain at 2200 m on the Duffey. The slabs were up to 20 cm in depth, failing on the March 8th surface hoar.
Snowpack Summary
Thursday and Friday's storm snow (10- 20 cm) is sitting on a slippery crust that is present at all elevations on solar aspects. Low elevation polar aspects also have a crust, but treeline and alpine elevations feature a mix of large surface hoar and surface facets.In the north of the region, polar aspects (those that face north and east) are harboring cold snow and a surface hoar interface buried early March that is about 30 cm below the surface. This layer exists at alpine and treeline elevations, but it is not everywhere. This layer has recently produced large human triggered avalanches in the north of the region but has not been reactive in the south of the region. Also in the north of the region a weak layer buried mid-February is about 40 to 80 cm below the surface and has been reactive in snowpack tests. The layer is composed of sugary facets, a sun crust on solar aspects, and surface hoar that is present at and below treeline. In the south of the region, around the Coquihalla and in Manning Park, the recent storm snow overlies a recent crust that caps a well settled snowpack.
Problems
Wind Slabs
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 25th, 2018 2:00PM