Avalanche Forecast

Issued: Nov 23rd, 2017 4:23PM

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

Avalanche Canada jmcbride, Avalanche Canada

Another storm event is on its way for the weekend. While this one is expected to be cooler than Wednesday's deluge, snowfall amounts are uncertain. Heavy snow, wind and rain will increase hazard.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Friday will see a continuation of Thursday's drying and cooling trend before the next wave of warm and wet precipitation returns on Saturday.FRIDAY: Flurries, accumulation 10-20 cm. Strong southwest wind. Alpine temperature -1. Freezing level 1200 m.SATURDAY: Snow, accumulation 20-30 cm. Moderate to Strong south wind. Alpine temperature 1. Freezing level 2000 m.SUNDAY: Wet snow or rain, accumulation 20-30 mm. Strong south wind. Alpine temperature 2. Freezing level 2200 m.

Avalanche Summary

Following the November 17-19 storm, a natural avalanche cycle produced storm slabs to size 3 on predominantly northerly aspects in the alpine and at treeline. Cornices were also touchy and large for this time of year and producing large avalanches after releasing onto slopes below. Subsequent warm weather and rain to mountain tops produced numerous loose, wet avalanches as rain drenched all elevations. Expect this activity to subside during the cooler drying trend on Friday but then increase again during the next storm event on the weekend.

Snowpack Summary

Cooler temperatures and lowering freezing levels have formed a 2 cm thick crust at 1800 m and above. Below this crust the upper snowpack is saturated down 30 cm to the November 21st crust at alpine elevations while at treeline and below the entire snowpack as been soaked through to ground. The November 9th crust/persistent weak layer combo near the bottom of the snowpack is now down 150 - 240 cm in alpine and glaciated terrain.

Problems

Loose Wet

An icon showing Loose Wet
Rain has soaked the snowpack to ground at treeline and below treeline elevations. It may be possible to trigger point releases in steep or unsupported features.
Use extra caution on slopes if the snow is moist or wet.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Storm Slabs

An icon showing Storm Slabs
Storm slabs will form in areas that receive new snow and wind.
Stay well to the windward side of corniced ridges.Avoid avalanche terrain during periods of heavy loading from new snow and wind.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 24th, 2017 2:00PM