Avalanche Forecast

Issued: May 4th, 2017 4:00PM

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

deryl kelly, Parks Canada

Jasper.

Still looks like winter in the higher elevations but change is coming rapidly. Significant rain and freezing level rising to mountain top.Hazard rating rising to Extreme for Friday, all day. Good day to stick to riding on the ski hill.

Summary

Weather Forecast

Progressive warming and significant precipitation forecast through the bulletin region for the weekend. Expect strong radiation with any direct sun. Freezing level rising to 3500m.

Snowpack Summary

Spring conditions on all aspects and elevations with a melt freeze crust that is dependent on overnight freezing conditions. The snowpack is moist to wet snow to ground below this crust.

Avalanche Summary

Avalanche activity will increase after warm nights and/or with thermal inputs such as rain, solar radiation and daytime warming. The avalanche danger will be lowest after cold nights and strong crust formation and will increase into the afternoon and evening before sunset. Likely trigger spots are rocks, cliffy terrain and shallow snowpack areas.

Confidence

Problems

Loose Wet

Freezing overnight temperatures decrease this danger in the morning, it increases with daytime heating, sun and rain. Most widespread during the late afternoon on solar facing slopes. Sluffs from rocks can trigger large slides once the snow is wet.

Pay attention to sluffing off cliffs and steep solar terrain, signs of a warming snowpack.Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wet Slabs

Large wet slabs up to size 4 have been observed on all aspects and elevations. Even small wet slabs can be quite destructive due to their density. Avoid traveling through avalanche terrain during the heat of the day.

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Cornices

Cornice failures are more likely with warm alpine temperatures.

Give cornices a wide berth when travelling on or below ridges.Avoid travel on slopes that are exposed to cornices overhead.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: May 5th, 2017 4:00PM