Avalanche Forecast

Issued: Jan 27th, 2015 4:53PM

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

rupert wedgwood, Parks Canada

Jasper.

Cooling temperatures over the next 72 hours will reduce the avalanche danger as the freezing level drops.

Summary

Weather Forecast

A drier and colder air mass is forecast to arrive on Wednesday. Freezing levels will fall to the valley bottom resulting in overnight freezing. Winds will be moderate from the west and south west. Snow is expected on Friday in townsite area.

Snowpack Summary

Over the past 24 hours precipitation has fallen as rain below 2,400m. At treeline, the heavier snow sits over a persistent weak layer dating to Dec 20th. Below treeline, isothermic conditions exist.

Avalanche Summary

Avalanche control, at and above treeline, produced numerous slab avalanches up to size 3 along the icefield parkway. At times the avalanche was triggered before the explosives detonated. Below 1,800m moist point release to size 2 are traveling to mid runout. and taking the snowpack to ground.

Confidence

Freezing levels are uncertain on Wednesday

Problems

Persistent Slabs

Heavy snow sits on the December weak layer. Any additional load such as a small point release can step down to this weak layer. Once the slide is moving, it will step down further to ground from the weight of the snowpack.

Be cautious as you transition into wind affected terrain.Avoid open slopes with any steepness over 30 degrees.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Wet

Cooling temperature will help to stabilize the moist snow which will occur most rapidly near treeline as the freezing level falls over the next 24 hours. Until this happens the snowpack at lower elevations will remain unstable and avalanche prone.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Avoid ice climbs that are in terrain traps below large start zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Storm Slabs

Strong SW winds over the past 48 hours has built slabs up to 60cm thick. This extra load combined with a skier will likely initiate an avalanche. As the wind reduce and temperatures drop the condition will improve.

Be careful with wind loaded pockets while approaching and climbing ice routes.If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Jan 28th, 2015 4:00PM