Avalanche Forecast

Issued: Apr 19th, 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.

garth lemke, Parks Canada

Jasper.

Daytime warming will increase the probability of cornice failures and avalanches. Ski quality is good with dust on crust. Low elevation crust remained intact again today.

Summary

Weather Forecast

Saturday will be scattered flurries, light rain at low elevations, and -9 to -2. Sunday will be cloudy periods. Expect temperatures to spike when the sun comes out. Monday will be sunny and spring conditions followed by scattered flurries on Tuesday. It will be spring conditions the rest of the week.

Snowpack Summary

Isolated windslabs on lee aspects at high elevation ridgecrests with a dusting of snow overtop. Buried temperature crusts below 2100m and sun crusts on steep solar aspects at various elevations. Cornices are big. Overall the snowpack is solid underfoot. Temperature crust maintaining last few days through the afternoon with cooler temperatures.

Avalanche Summary

No new avalanches observed today. Visibility was good. Generally the area is in a stable trend but investigate each slope individually for isolated windslabs before committing.

Confidence

Problems

Loose Wet

If the sun comes out or the day is exceptionally warm, expect increased frequency of loose wet slides to occur particularly on steep solar aspects.

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

Test slopes before committing to them.

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.

Cornices become weak with daytime heating.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 20th, 2013 4:00PM