Avalanche Forecast

Issued: Feb 7th, 2019 8:00AM

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

mark herbison, Parks Canada

Glacier.

Variable distribution of wind slab in the alpine and buried surface hoar layers at tree line and below demand your attention. Choose low consequence terrain, human triggered avalanches are possible.

Summary

Weather Forecast

Cold and cloudy with little chance of seeing the sun makes me want to stay inside today... but I won't. Alpine high of -16 with isolated flurries (~2cm for the day) and light ridge top winds from the South West. Friday will be similar to today, cold temps and clear skies for the weekend.

Snowpack Summary

A thin sun crust has formed on steep solar aspects in alpine. Cold temps promoting near surface faceting and softening wind slabs that exist in alpine and exposed areas at tree line. The storm snow has settled has to ~50cm. The Jan 31 and Jan 17 interfaces (surface hoar and sun crust) are down ~50cm and ~70cm at tree line.

Avalanche Summary

A skier triggered size 2.0 yesterday from steep, exposed terrain on Glacier Crest as well as a natural cornice triggered size 2.0 in 'Rail Road Gunners'. There was a large natural cycle over the weekend with many slides running full path.

Confidence

Due to the quality of field observations

Problems

Persistent Slabs

The Jan 31 and Jan 17 surface hoar layers are down ~50 and ~70cm respectively. This layer exists on all aspects, and is most problematic between 1400-1900m and on steep solar aspects where it overlies a crust.

Caution on open slopes and convex rolls at treeline and below, buried surface hoar may be preserved.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Wind Slabs

Last weekends storm snow and strong variable winds created wind slabs in the alpine and exposed areas at tree line. Skiers are find this problem most reactive along ridge crest and cross loaded terrain features.

Watch for whumpfing, hollow sounds, and shooting cracks.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Feb 8th, 2019 8:00AM