Avalanche Forecast

Issued: Mar 19th, 2018 4:00PM

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

landon shepherd, Parks Canada

Jasper.

Snowfall amounts on Thursday are expected to be light, but elevated accumulations would increase the avalanche danger.

Summary

Weather Forecast

Cont' broken skies and light flurries, mild temps and moderate overnight recovery of surface crusts. Light to mod westerly winds until Thursday.Thursday-Fri. Winds increase and shift South as a trough sweeps through with 10-15cm of snowfall. Freezing levels should edge upward and top 2000m on Thursday but otherwise remain below treeline.

Snowpack Summary

10-15cm of dense snow week over 4 days has created thin storm slabs which have bonded well at treeline and below, but may remain reactive on alpine shaded aspects. Loose wet slides are likely below treeline in the late afternoon (particularly with direct sun). Facets buried beneath February's multiple windslabs may still produce thin slabs.

Avalanche Summary

A road patrol Sunday noted solar aspects treeline and below have been producing loose wet avalanches to size 1 for several days. An isolated large avalanche (size 2.5) which occurred on a steep rock slab, on a NE aspect in the alpine (2500m) had slid in the last few days. The dimensions of this slab were 300m wide by 100cm deep.

Confidence

Freezing levels are uncertain on Wednesday

Problems

Storm Slabs

Storm slabs sit on a hard melt-freeze crust on solar aspects, and facets on polar aspects. Assess the bond at these interfaces carefully before committing to avalanche start zones.

Use caution in lee areas. Recent wind loading have created storm slabs.Use safe ski cutting techniques before entering ski run.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Wet

Watch for snowpack to become reactive if the sun comes out.

Use caution above cliffs where small avalanches may have severe consequences.Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Mar 20th, 2018 4:00PM