Avalanche Forecast

Issued: Jan 31st, 2015 4:21PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Deep Persistent Slabs.

a.l. horton, Parks Canada

Jasper.

Sensible decision making was observed in the Parkers Area today by field team. Skiers are respecting the sensitive storm slab conditions that exist.

Summary

Weather Forecast

Clear overnight with clouds and snow moving in by noon on Sunday. 4-6 cm expected with light SW winds. Temps remaining seasonal.

Snowpack Summary

Recent warm temperatures and rain followed by cooler temps have produced a widespread crust up to 2400m on all aspects. Above this, previous wind affected surfaces in exposed areas and wind slabs on lee aspects. 15-20 cm of storm snow is now sitting over this crust and has blown into wind slabs at tree line and above.

Avalanche Summary

An avalanche cycle has taken place in the last 24 hrs. Numerous solar triggered size 2 slab and loose snow avalanches at tree line and sub alpine on W aspects failing on the rain crust. 3 size 2 slab avalanches on E aspects failing on rain crust at tree line and above. Size 3 explosive triggered avalanche at Marmot stepped down to Nov crust.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Tuesday

Problems

Storm Slabs

The interface between storm snow and the melt-freeze crust from the recent warm temperatures warrants investigation. Touchy conditions should be expected in steep terrain, on all aspects below 2400m.

Avoid steep lee and cross-loaded featuresBe cautious of sluffing in steep terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Deep Persistent Slabs

This layer remains a concern in isolated areas above treeline and may be triggered by large loads such as cornices or from shallow areas by skiers. Explosive control work yielded big results at Marmot on Saturday on this interface.

Avoid steep slopes below cornices.Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Feb 1st, 2015 4:00PM