Avalanche Forecast

Issued: Apr 12th, 2017 4:00PM

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

aaron beardmore, Parks Canada

Banff Yoho Kootenay.

Although forecasted amounts of snow are minimal, act accordingly if more snow than expected is encountered.

Summary

Weather Forecast

A system has built into the forecast region which will bring light amounts of precip amounting to about 10cm over the next 36 hours. Wind will remain light from the SE. Temperatures will be cooler than seasonal with valley bottom just above 0 and 3000m temps hovering around -10.

Snowpack Summary

Small amounts of snow over the weekend have added up to about 20-40cm. This new snow is generally bonding well with some isolated pockets of wind slab in the alpine. Below tree line the surface snow is moist on solar aspects. At tree line and above a 120cm+ firm slab with few weaknesses overlies weaker basal facets in much of the region.

Avalanche Summary

No new avalanches observed or reported on Wednesday.

Confidence

Intensity of incoming weather systems is uncertain on Thursday

Problems

Deep Persistent Slabs

The snowpack is gaining strength, but the weak basal facets continue to produce sudden collapse results and can produce large avalanches with large triggers. Stick to planar, supported slopes with a deeper snowpack if entering steep terrain.

Be aware of thin areas that may propogate to deeper instabilites.Pay attention to overhead hazards like cornices which could easily trigger deep slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Cornices

April is cornice failure season, and we continue to get reports of cornices failing and triggering deep slabs. Mature cornices can also break much further back than you expect, so give them a wide margin when traveling on ridges.

Do not travel on slopes that are exposed to cornices overhead.Stay well to the windward side of corniced ridges.

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Apr 13th, 2017 4:00PM