Avalanche Forecast

Issued: Dec 17th, 2019 8:00AM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Loose Dry.

chris gooliaff, Parks Canada

Glacier.

Keep your head up today!

Limit your exposure to overhead avalanche paths. The light, dry powder is creating fast, far-reaching avalanches that are quietly zipping into valley bottoms with little sound.

Summary

Weather Forecast

Continued snowfall adding up to another 10-15cm in the next 24hrs. Winds should increase to mod/strong from the SW with alpine temps reaching -7*C. Flurries for Wed, bringing another 8cm with mod/strong gusty SW winds and alpine temp of -6*C. Thursday shows a slackening in snow, but Fri/Sat could deliver another 25-30cm with winds and warmth.

Snowpack Summary

40cm of new snow now buries the Dec 11 surface hoar layer. Moderate S'ly winds are building storm slabs in the Alpine. The Nov 23rd surface hoar/crust/facet combo is down +/-100cm (SH is most prevalent in sheltered treeline locations) but has become increasingly stubborn in testing. The mid-lower snowpack is settled and strong.

Avalanche Summary

Natural avalanche activity to sz 2.5 began overnight and continues this morning in many highway-facing start zones. The loose, dry avalanches are traveling far and fast, reaching valley bottom and dusting up-tracks and the road.

Confidence

Problems

Storm Slabs

Up to 40 cm of new snow since Dec 11th with increasing SW winds. Expect a reactive storm slab in wind exposed features.

Watch for fresh storm slabs on exposed lee slopes at and above treeline.
Minimize overhead exposure during periods of heavy loading from new snow, wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Loose Dry

Surface snow will be prone to sluffing, especially on steep, unsupported aspects. Sluffs are running fast and far, picking up more snow as it flows down gullies.

Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.
Be aware of party members below you that may be exposed to your sluffs.