Avalanche Forecast

Issued: Mar 13th, 2013 4:00PM

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

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

Natural avalanches are likely. We are in a natural avalanche cycle, and will be for the next 24 hours.

Summary

Weather Forecast

A second pulse from the pineapple express will hit the Rockies tonight and tomorrow, bringing up to 30cm of snow at higher elevations and rain below 1900m. Winds will be moderate to strong from the west. Temperatures will continue to be mild for this time of year (freezing level rising to 1900m), with no cooling overnight.

Snowpack Summary

A warm, windy night brought 15-20cm of dense snow. This has created very touchy storm slabs in the alpine and at tree-line. Below tree-line, there was rain to 1900m, creating unstable surface conditions.

Avalanche Summary

We are currently in a natural avalanche cycle, and will be for the next 24 hours at least. A field team in Yoho remotely triggered a size 2 slab avalanche while moving through moraines above Takakkaw Falls. They noted that conditions were very touchy and retreated. Below tree-line, numerous loose slides to size 1.5 were observed in Yoho.

Confidence

Problems

Storm Slabs

Dense, very touchy storm slabs developed overnight with the new snow and warm temperatures. More snow is forecasted for the next 24 hours.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Wind Slabs

Strong W winds will be developing wind slabs on lee aspects and will be sensitive to human triggering.

Avoid all avalanche terrain.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Loose Wet

Rain to 1900m has created unstable conditions below tree-line. Travel is not recommended.

Good day to make conservative terrain choices.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 14th, 2013 4:00PM