Avalanche Forecast

Issued: Apr 20th, 2013 4:00PM

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

mike eder, Parks Canada

Jasper.

Good spring skiing can be found in the lower alpine and around treeline.

Summary

Weather Forecast

Overcast skies and flurries are expected to bring light snow accumulations onto the Eastern slopes in the next 24 hours. Winds will be light to moderate from the Northeast and a clearing trend will begin later in the day. Monday will see slightly warmer temperatures and scattered clouds with no precipitation to speak of.

Snowpack Summary

Spring conditions are mostly solid with up to 15cm of snow on the crust layer. In the alpine, wind slabs exist on lee aspects near ridge tops. Sun crusts are well developed on steep, solar aspects. Overcast skies and cooler temperatures have kept the crusts intact even at lower elevations.

Avalanche Summary

One avalanche was reported yesterday above the icefalls on the Athabasca glacier which originated from steep, cross loaded gullies in the high alpine. Cooler temperatures and no solar radiation due to cloud cover has reduced natural activity in the last few days.

Confidence

Problems

Loose Wet

Sunny periods combined with warmer temperatures will increase this avalanche activity from steep solar aspects and gully features.

Minimize exposure to sun exposed slopes when the solar radiation is strong.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

Isolated pockets of wind slab can be found on lee aspects in exposed alpine terrain near ridge crests. The likelihood of triggering avalanches increases when the day heats up or the sun comes out. Test the bond to the underlying crust.

Be careful with wind loaded pockets

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Cornices

Cornices are large and a hazard by their sheer mass. They have the potential to trigger deeper layers if they fail big.

Do not travel on slopes that are exposed to cornices overhead.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 21st, 2013 4:00PM