Avalanche Forecast

Issued: Mar 1st, 2017 4:21PM

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

cam_c, Avalanche Canada

Kootenay Boundary.

Heavy snowfall and wind has resulted in HIGH avalanche danger at higher elevations.

Summary

Confidence

Moderate -

Weather Forecast

THURSDAY: Another 5 to 10 cm is expected by Thursday evening with SW winds. Continued warm with freezing level steady around 1300mFRIDAY: Still snowing with 10 to 20cm forecast by Friday evening with strong SW winds. Continued warm with freezing level unchanged (around 1300m).SATURDAY: Scattered flurries with light snowfall, moderate southwesterly winds and freezing levels around 1000 m.

Avalanche Summary

Explosive control at treeline and alpine elevations released storm slabs 30 to 60 cm deep on Monday. Loose dry sluffing up to size 1.5 from steep terrain at all elevations was also reported on Monday and Tuesday. Slab avalanche size and likelihood is expected to increase with forecast new snow, wind, and warming.

Snowpack Summary

Another 10-20cm adds to the 30 to 50 cm from the past few days with deepest amounts in eastern areas. Wind slabs have formed in exposed areas from shifting SW to NW winds and more snow and wind is forecast. Recent snow rests on a sun crust on steep sun-exposed slopes and large surface hoar shaded aspects. Below that are a variety crusts and thin surface hoar layers, depending on aspect and elevation, with the primary mid-pack feature being the mid-February surface hoar/sun crust down 75-100 cm. 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.

Problems

Storm Slabs

New snow will become more reactive as warming temperatures and wind promote slab development. Shifting S to W winds may see touchy wind slabs form behind ridges and ribs, but also in open treeline areas.

Minimize overhead exposure during periods of heavy loading from new snow, wind.Be cautious as you transition into wind affected terrain.Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Loose Dry

Although generally harmless, loose snow sluffs have the potential to take you for a ride, which could have dire consequences if terrain traps are in the runout.

On steep slopes, pull over periodically or cut into a new line to manage sluffing.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 2nd, 2017 2:00PM