Avalanche Forecast

Issued: Apr 18th, 2015 8:00AM

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

andrew jones, Parks Canada

Glacier.

Spring is here. It's best to go out early and be back before conditions deteriorate from daytime warming.

Summary

Weather Forecast

Warm and dry weather is expected for the next several days. Sunny today with freezing levels climbing to 2000m and moderate NW winds. Freezing levels will drop to 1400m tonight, but remain high over the next couple of days, reaching 3000m on Tuesday.

Snowpack Summary

Rogers Pass received 10mm of rain yesterday with above freezing temperatures in the alpine. A modest overnight refreeze created a surface crust over moist or wet snow. Crust will soften today with sunny periods and freezing levels rising to 2000m. A weak layer down 50cm sits on a crust on solar aspects and surface hoar on sheltered NE aspects.

Avalanche Summary

A size 2.0 glide crack avalanche was observed from the highway corridor on Mt Tupper.

Confidence

Problems

Persistent Slabs

A slab sits on a persistent weak layer buried 40-60cm or deeper where strong winds have deposited snow in lee areas. The layer is surface hoar on NE aspects and a sun crust on S aspects. Sun, loose avalanches and skiers can trigger this layer.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

10mm of rain from yesterday added moisture to an already warm snowpack. When the strong spring sun hits the slopes, expect to see surface snow on the move. Loose slides can dig down to wet snow deeper in the snowpack resulting in larger avalanches.

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Large cornices have the potential to fall with the addition of sun and warming. Remember that cornices above shaded slopes are being warmed from behind by the sun. Cornices will be most dangerous during the height of daytime warming in the afternoon.

Cornices become weak with daytime heating, so travel early on exposed slopes.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 19th, 2015 8:00AM