Archived

Avalanche Forecast

May 2nd, 2017–May 3rd, 2017

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Alpine

Below Threshold

The avalanche danger rating in the alpine will be below threshold

Treeline

Below Threshold

The avalanche danger rating at treeline will be below threshold

Below Treeline

Below Threshold

The avalanche danger rating below treeline will be below threshold

Regions: Jasper.

Progressive warming and no overnight freeze is forecasted for the week of May 3 through to May 5th. Widespread avalanche cycle is expected. Check Alberta511 for up to date road closures on Maligne road and Hwy 93 for Wednesday through Friday.

Weather Forecast

Rapid progressive warming expected by Wednesday evening and leading into the weekend. Mix of light precipitation and broken skies. Expect strong radiation with any direct sun. Freezing level rising to 3000m by midnight on Wednesday.

Snowpack Summary

Winter conditions exist in the high alpine on Northerly slopes with up to 20 cm of loose new snow sitting over a well consolidated upper snowpack. Spring conditions exist on all other 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

Avalanche 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.

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

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Cornices

Cornice failures are more likely with warm alpine temperatures.

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

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 2 - 3

Deep Persistent Slabs

The deep instability is well bridged by a solid mid-pack; however, it could be triggered by a cornice failure. This problem will transition to wet slabs as the snowpack warms this spring.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 4