Avalanche Forecast

Issued: Feb 23rd, 2013 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs, Loose Dry and Cornices.

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

There's variability in danger in the region. Areas immediately along the Divide saw up to 20cm of new snow, locally increasing the danger rating. East of the Divide saw a dusting, thus, a lower danger. If it dumped where you are, keep your eyes open.

Summary

Weather Forecast

Tomorrow we should see increasing clouds with possibly 5-10cm late in the day. Moderate west winds will accompany this storm. Monday will have unsettled convective cells rolling through, with little in the way of snow for us.

Snowpack Summary

Up to 20cm reported over last 24 hours in the alpine immediately along the Divide. Some thin ridgetop soft wind slab formation in immediate ridge top lees. This snow sits on top of wind slabs, both soft and hard, in alpine areas. Thin snowpack areas at all elevations are very weak and faceted, as are most below treeline areas up to 1900 meters.

Avalanche Summary

Large sloughing was observed off the Stanley Headwall, likely due to strong winds at ridge-top. Experienced climbers in the area said they were large enough to knock climbers off their intended routes. Point releases from steep terrain were observed further south in Kootenay, all in the recent snow.

Confidence

Forecast snowfall amounts are uncertain

Problems

Wind Slabs

Soft slabs in the high alpine are developing with the recent snow and winds. The next system late tomorrow could create further wind slabs. Expect these to be touchy within the next 24 hours.

Avoid freshly wind loaded features.Carefully evaluate and use caution around thin snowpack areas.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Expect sloughing in steep gully terrain. A field team in Kootenay noted large enough sloughs to knock a person around. Ice climbers should monitor this closely.

Be cautious of sluffing in steep terrain.Be aware of party members below you that may be exposed to your sluffs.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Cornices can provide the big trigger and entrain new wind slabs and underlying facets. Some of these cornices have been easily triggered in the last week.

Give cornices a wide berth when travelling on or below ridges.Pay attention to overhead hazards like cornices.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Feb 24th, 2013 4:00PM