Avalanche Forecast

Issued: Feb 27th, 2018 4:00PM

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

landon shepherd, Parks Canada

Jasper.

Summary

Weather Forecast

Flurries and mild temperatures are expected this week with a brief pulse of warm air and freezing levels rising to treeline on Thursday. Total snowfall should be less than 10cm over the week.

Snowpack Summary

Old wind slabs and extensive wind effect found in all open areas. The upper snowpack is a 50 to 80 cm deep slab that sits on three weak layers in the mid-pack. The entire snowpack is faceting after two weeks of cold, dry weather. Whumpfing and collapses are more prevalent in the northern half of the forecast area.

Avalanche Summary

Limited avalanche activity since the extensive avalanche cycle on February 8-9. Slopes that did not avalanche during this cycle should still be carefully assessed.

Confidence

Problems

Persistent Slabs

A 50 to 80cm thick slab, sits over sun Crusts (south and west aspects), Surface Hoar (at, and just above treeline) and weak Faceted Crystals (very developed in shallow snowpack features). Faceting has reduced slab strength in shallow and BTL areas.

Be wary of slopes that did not previously avalanche.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3.5

Wind Slabs

Expect hardslabs in the alpine and a few softer slabs at treeline. The cold has kept these in check and helped them settle over the last few days but some caution is still warranted especially as new snow and winds arrive over the next few days.

If triggered the wind slabs may step down to deeper facet layers resulting in larger avalanches.Best conditions on sheltered northerly aspects.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 28th, 2018 4:00PM