Avalanche Forecast
Issued: Mar 20th, 2018 5:01PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
High -
Weather Forecast
Wednesday: Mainly cloudy with isolated flurries and a trace of new snow. Light to moderate southeast winds, increasing overnight. Freezing level to 1600 metres with alpine high temperatures around -4.Thursday: Mainly cloudy with isolated flurries and a trace of new snow, increasing overnight. Moderate to strong southeast winds. Freezing level to 2100 metres with alpine high temperatures around 0 to +1.Friday: Mainly cloudy with continuing isolated flurries and a trace of new snow. Light to moderate southwest winds. Freezing level to 1300 metres with alpine high temperatures around -7.
Avalanche Summary
Reports from Sunday included a remotely (from a distance) triggered 25 cm deep storm slab (size 1) releasing with skier traffic on a steeper north-facing slope at around 2000 m in the Monashees. Several more natural size 2 storm slab releases were observed on very steep northeast-facing terrain at around the same elevation. These occurred during the peak of daytime warming.On Saturday there were numerous reports of size 1-2, loose wet avalanches on sunny, solar aspects involving the recent storm storm snow, as well as one report of a size 1.5 skier triggered slab (30 cm deep) on a northwest aspect at 2000 m.Last Friday there were reports of several skier triggered (size 1-1.5) avalanches from 15-25 cm deep on north through southeast aspects between 1700-2100 m.
Snowpack Summary
Recent light snowfalls have been followed by warm daytime temperatures and glimpses of sun, setting up a couple of thin storm snow layers over temperature and sun crusts at lower elevations and on south aspects. On shaded aspects at higher elevations, these snowfalls have buried and preserved a couple of surface hoar layers now found up to 30 cm deep. The deepest of these surface hoar layers has been the failure plane in several recent slab avalanches.New snow amounts taper with elevation and below 1800 m, minimal accumulations have buried a supportive crust on all aspects. This crust will likely break down with daytime warming, becoming moist in the afternoon. Deeper persistent weak layers from January and December are generally considered dormant, but could wake up with a surface avalanche stepping down, large cornice fall, or a human trigger in a shallow or variable-depth snowpack area. These layers consist of sun crust, surface hoar and/or facets.
Problems
Storm Slabs
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 21st, 2018 2:00PM