Avalanche Forecast

Issued: Nov 28th, 2015 4:00PM

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

a.l. horton, Parks Canada

Jasper.

Ice climbers should beware of temperature inversion conditions on steep solar exposed climbs that are producing large avalanches. Avoid these areas until temperatures cool on Monday.

Summary

Weather Forecast

Inversion conditions to continue on Sunday with freezing levels between 2100 and 3000m. The inversion weakens on Monday. Winds remain light, with cold temperatures overnight in valley bottoms. No precipitation until late next week.

Snowpack Summary

Previous frigid temperatures have weakened the snowpack. Whumphing noted on pockets of windslab in exposed areas around treeline. Alpine is scoured in wind exposed areas. Surface hoar formation and faceting is widespread. Warm temps in past 48hrs producing thin sun crust on solar aspects at treeline and above.

Avalanche Summary

Numerous loose dry avalanches up to size 2.5 noted on Saturday afternoon in steep solar facing gulleys between 2100 and 2700 m. Whumphing observed in open areas at treeline on windslab. No avalanche propagation observed but possible on steeper slopes.

Confidence

Freezing levels are uncertain on Monday

Problems

Loose Dry

Temperature inversion continues with cold valley bottom temps and above freezing temps at treeline and above. Warm temps combined with solar effect on steep gulley features are producing loose snow releases. This will be a concern to ice climbers.

The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.Avoid ice climbs that are exposed to steep rocky terrain on solar aspects.

Aspects: North, North East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

North winds have formed wind slabs on isolated terrain features at upper elevations.

Be cautious as you transition into wind affected terrain.Watch for whumpfing, hollow sounds, and shooting cracks.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Nov 29th, 2015 4:00PM