Avalanche Forecast

Issued: Dec 13th, 2020 8:01AM

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

Mike Smallwood,

Field teams yesterday found loose sluffs to have more mass than expected, watch for terrain traps and people below you

Summary

Weather Forecast

Light snow and overcast today, tonight and tomorrow. Snowfall intensifying early Tuesday morning with up to 10cm by end of day Tuesday and 25cm by Wednesday. Wind will also pick up on Tuesday afternoon to strong from the W. The incoming system will also bring a rising temperature trend with a high of -10 today, -8 tomorrow and -7 on Wednesday.

Snowpack Summary

30cm of storm snow from Monday and Tuesday buried a variety of surfaces; surface hoar up to 10mm which is rounding in some areas; a localized thin crust from freezing rain in and around the Connaught creek drainage, and a crust on steeper solar aspects from sunny breaks. The Nov 5 crust is down between 1m and 1.5m

Avalanche Summary

Skier triggered sluffing in steep terrain yesterday was significant enough to be of concern around terrain traps.

There was a MIN report of a skier triggered small avalanche in the alpine on Friday.

Several small-large solar triggered loose dry avalanches were observed in the last few days in the highway corridor from N and S aspects.

Confidence

Due to the quality of field observations on Sunday

Problems

Loose Dry

An icon showing Loose Dry

Cold temperatures and relatively light winds in most of the park have left unconsolidated snow with enough mass to push skiers and riders around even in open terrain. Extra care is required around cliffs and confined gullies

  • Be careful of loose dry power sluffing in steep terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

A 30cm slab sits on the Dec 7th weak interface of rain crust/sun crust/surface hoar combo. Recent slab avalanches have failed on this layer. This layer could be more reactive in isolated terrain features that experienced more wind

  • Caution on open slopes and convex rolls at treeline and below, buried surface hoar may be preserved.
  • Persistent slabs may be more sensitive to human triggering on solar asp where it sits on sun crust

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 14th, 2020 8:00AM