Avalanche Forecast

Issued: Mar 3rd, 2017 5:05PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is moderate. Known problems include Storm Slabs.

Avalanche Canada ghelgeson, Avalanche Canada

Strong SW wind and fresh snow Friday night may fuel another round of natural avalanches while most of us sleep. Light wind and lack of snowfall on Saturday may appear benign, but the mountains are currently primed for human triggered avalanches.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Saturday

Weather Forecast

A deep upper trough is moving through BC this weekend. The unsettled weather pattern should deliver continued precipitation and southwesterly winds to the mountains of the Kootenay Boundary through the forecast period. FRIDAY NIGHT: 5 to 20 cm of snow, strong to extreme southwest wind.SATURDAY: Overcast skies, freezing level beginning around 500m rising to 1000m in the afternoon, moderate SW wind, 5 to 10 cm of snow. SUNDAY: Overcast skies, freezing level beginning around valley bottom rising to 500m in the afternoon, light SW wind, 1 to 5 cm of snow. MONDAY: Overcast skies, freezing level beginning around valley bottom rising to 500m in the afternoon, moderate SW wind, 1 to 5 cm of snow.Visit avalanche.ca/weather for a more detailed mountain weather forecast.

Avalanche Summary

On Thursday control work produced storm slab avalanches to size 1.5 on NE, E and SE facing slopes. Reports from Wednesday include numerous natural, skier and explosive triggered storm/wind slab avalanches up to Size 2.

Snowpack Summary

30 to 80cm of snow has fallen in the last week, which is bonding poorly to a sun crust on previously sun-exposed slopes, or facets and large surface hoar on shaded aspects. Wind slabs have formed in exposed areas from winds out of the NW and now SW, with continued snow and wind forecast for Friday night and Saturday. A variety of crusts and thin surface hoar layers in the upper snowpack are becoming more of a concern with this increased load. Areas with a shallow snowpack (less than around 170 cm) generally have a weak snowpack structure with a deep persistent weakness of facets near the ground. There are a number of great MIN reports from Thursday and Friday here: http://www.avalanche.ca/mountain-information-network/submissions/

Problems

Storm Slabs

An icon showing Storm Slabs
Ongoing snowfall coupled with strong SW wind is fueling a robust storm slab problem that is particularly problematic in wind exposed terrain, as a result the safest and conveniently best riding will be found in wind sheltered terrain below treeline.
Use cautious decision making and select conservative terrain this weekend.Think carefully and have a good reason for traveling into wind exposed terrain.Avoid all avalanche terrain during periods of heavy loading from new snow and/or wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 4th, 2017 2:00PM