Avalanche Forecast

Issued: Nov 24th, 2017 4:59PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Wet and Storm Slabs.

jmcbride, Avalanche Canada

South Coast.

Wet, warm weather forecasted for Friday night and into the weekend means the potential for loose, wet avalanches in extreme terrain and pockets of storm slab in areas that receive snow instead or rain.

Summary

Confidence

Weather Forecast

The next wave of warm, wet weather is expected to hit the South Coast by Saturday morning.Saturday: Wet snow or rain, accumulation 20-30 mm. Moderate to strong south wind. Alpine temperature 2. Freezing level 1600m.Sunday: Rain, accumulation 30-40 mm. Strong south wind. Alpine temperature 5. Freezing level 2500m.Monday: Flurries, accumulation 10-15 cm. Light to moderate southwest wind. Alpine temperature -1. Freezing level 1000 m.

Avalanche Summary

No recent avalanches have been reported. However, the recent rain-on-snow event is suspected to have caused a natural, loose wet avalanche cycle. Although natural avalanche activity and human triggering potential has decreased with cooler temperatures, ongoing rain will maintain the potential for loose wet avalanches, particularly in steep, unsupported terrain. Storm slab development is also a concern at high alpine elevations where precipitation may fall as snow accompanied with strong winds.

Snowpack Summary

There is little information on snowpack structure at this time, except that recent heavy rainfall has saturated the upper snowpack at all elevations and washed away much of the snow at lower elevations. Snow depth varies from 45 - 130 cm for elevations between 900 - 1200m across the region.

Problems

Loose Wet

Rain has saturated the upper snowpack and potential for loose wet avalanches exists on steep, unsupported terrain features. Even a small loose wet avalanche can gain enough mass to become a big problem.

Be cautious of wet sloughs in steep terrain, particularly where the debris flows into terrain traps.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Storm Slabs

Be aware that storm slabs may exist in the high alpine. Dial back your terrain selection if you find the snow surface changing from wet snow to new snow as you gain elevation.

Be alert to conditions that change with elevation.Use extra caution in lee areas in the alpine. Storm snow may be forming touchy slabs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 25th, 2017 2:00PM