Avalanche Forecast

Issued: Feb 20th, 2016 8:00AM

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

Parks Canada danyelle magnan, Parks Canada

http://www.pc.gc.ca/apps/links/goto_e.asp?destination=Periods of strong solar, combined with an unpredictable layer down ~1m and a busy weekend will make decision making complicated. Avoid exposure to slopes threatened by cornices, that are hammered by the sun, and consider who is above and below you!

Summary

Weather Forecast

Today expect flurries to taper off, with increasing sun this afternoon. This will be the first real sun on the slopes since the storm and brief, intense periods of sun may trigger avalanches.  S-W winds will load lee slopes. Sun should start out sunny, but we may see more cloud in the afternoon with flurries. Mon should be cloudy with flurries.

Snowpack Summary

Reactive soft slabs have formed. Strong S'ly winds have formed windslabs. Snowpack tests indicate that weaknesses exist within the storm snow as well as on a persistent weak layer down 60-100cm. This layer appears to be most reactive on S'ly aspects, and tests show that avalanches may step down to this layer. Large cornices loom in many areas.

Avalanche Summary

Over the past few days, skiers have been triggering size 1-1.5 avalanches at treeline and above. These soft slabs are generally 10-30cm deep and some are running long distances. Natural avalanches are occurring from steep avalanche paths with start zones that are loaded by S'ly winds. These size 2.5 to 3 avalanches ran well onto the avalanche fans.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Storm Slabs

An icon showing Storm Slabs
Touchy storm slabs have formed in some areas. On steep slopes, especially ridgecrests, roll-overs and areas exposed to wind, expect slabs to be easily triggered. These soft slabs move fast and can accumulate in terrain traps.
Use safe ski cutting techniques before entering ski run. Ski short pitches and regroup in safe spots.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
A weak layer down 60-100cm is a wild card. It could pop up anywhere but tests indicate it is more reactive on solar aspects, the same slopes that will be hit by the sun if it comes out. Strong solar could wake this layer up.
Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.Caution around convexities or areas with a thin or variable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 4

Valid until: Feb 21st, 2016 8:00AM