Avalanche Forecast

Issued: Mar 29th, 2018 4:00PM

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

Tim Haggarty, Parks Canada

Jasper.

Highway 93 from Athabasca Falls to the Saskatchewan River Crossing is now closed (as of 14:00 Thursday March 29) for the anticipated completion of avalanche control work Friday March 30 and Saturday March 31. Please plan accordingly

Summary

Weather Forecast

Snow is forecast to begin falling over the region Thursday evening as a strong pacifc flow collides with an arctic front almost directly overhead. 15 to 20cm are expected through Friday afternoon. Watch for winds to shift from SW to E Friday morning and temperatures to drop as the cold air pushes back. Skies will clear Saturday under the arctic air

Snowpack Summary

Wind slabs up to 50cm thick sit on a sun-crust on solar aspects and facets on polar aspects. Heating in early March created some strength in the upper snowpack (mainly BTL and on solar aspects) however some deep slabs resulting from recent loading on N and E aspects in the lower alpine indicate that weakness in the mid and lower snowpack persist.

Avalanche Summary

A morning patrol of the 93N revealed several slabs on the west side of the highway. A few slabs up to 40cm thick were seen on solar slopes. Several slabs were seen on N and E slopes from 2300m to 2600m. Most of these were 20 to 60cm deep however two sz 3 slabs were seen where cornices had likely failed taking slabs 300m wide and 80cm to 100cm deep.

Confidence

Intensity of incoming weather systems is uncertain on Thursday

Problems

Wind Slabs

Wind 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 to a slope.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Cornices

Pay attention to overhead hazards like cornices which could easily trigger deep slabs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Mar 30th, 2018 4:00PM