Avalanche Forecast

Issued: Nov 19th, 2013 4:17PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Lots of snow is available for transport. Tricky conditions at higher elevations will exist until the snow has time to settle and bond to the layers below. SH

Summary

Weather Forecast

It should dip below -20C tonight and alpine winds will shift to N/NW up to 65kmh for Wed. Thursday and Friday should only produce trace amounts of snow with slightly warmer temperatures.

Snowpack Summary

15-30cm over the last 24 hours, starting as dense snow which became lighter as temps cooled. Up to 50cm settled storm snow over the last few days. Many areas reporting less accumulation in the alpine. Moderate winds SW to NW creating wind slabs 20-50cm thick in the alpine, The basal Oct. crust can still be found on polar aspects in the alpine.

Avalanche Summary

Avalanche work at Sunshine produced avalanches to size 2 on many different aspects, one of which stepped down to the Oct. crust in a previously uncontrolled alpine area. Less snow reported at Lake Louise, and less activity seen. Limited visibility, but some naturals were observed to size 2.5 on Pilot Mtn. during a clearing.

Confidence

Due to the number of field observations on Tuesday

Problems

Wind Slabs

Stiffer wind slabs 20-50cm thick in exposed areas. NW winds Wed. will load SE slopes but expect to find these on numerous aspects.

Use caution in lee areas in the alpine. Recent wind loading have created wind slabs.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Storm Slabs

Sunshine reporting a touchy storm slab interface down 40-80 cm. This needs time to bond to the previous surface below. Slides initiated on this layer could step down to basal facets or the Oct. melt/freeze crust where present.

Use caution in lee areas in the alpine and treeline. Recent storm snow has formed touchy slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Dry

Lots of snow available for transport and sluffing will be a major concern in terrain traps. Ice climbs below treeline such as Mt. Dennis will be prone to sluffing, especially if the winds pick up Wed.

Be cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 20th, 2013 4:00PM