Avalanche Forecast

Issued: Feb 19th, 2016 8:08AM

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

danyelle magnan, Parks Canada

Glacier.

Decision making is complicated right now. A tricky snowpack, unsettled weather, the potential for strong solar and a busy upcoming weekend could spell trouble.

Summary

Weather Forecast

Unsettled weather with flurries, mild temps and moderte S'ly winds is expected today, but brief periods of intense precipitation are possible. Overnight we are expected to receive 10-15cm. Sat and Sun expect a mix of sun and cloud with isolated flurries, alpine temps -5 to -10, and S'ly winds. Brief, intense periods of sun may trigger avalanches.

Snowpack Summary

New, reactive soft slabs developed yesterday at treeline and above with intense snowfall and windloading. Last weeks storm snow is settling, but snowpack tests still indicate that weaknesses exist within the storm snow as well as below. Tests show the potential for step-down to lower layers if triggered. Large cornices loom in many areas.

Avalanche Summary

Yesterday a brief, intense storm triggered a natural avalanche cycle from steep avalanche paths. Numerous size 2.5 to 3 avalanches ran well onto the avalanche fans. In addition, skiers were able to ski cut numerous very soft slab size 1-1.5 avalanches. They were 10-20cm deep on N-E aspects at treeline, and ran until the slope angle decreased.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Storm Slabs

New, touchy storm slabs are forming with ongoing snowfall and wind-loading. On steep slopes, especially areas exposed to wind, expect slabs to be easily triggered. While they aren't very deep (yet) they move fast and can accumulate in terrain traps.

Ski short pitches and regroup in safe spots.Use safe ski cutting techniques before entering ski run.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

Although the snow from the recent storms is settling and slowly bonding, tests still indicate that a layer now down 60-100cm is reactive in some areas. It is likely to take a large trigger, like a cornice or another avalanche.

Caution around convexities or areas with a thin or variable snowpack.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

3 - 4

Valid until: Feb 20th, 2016 8:00AM