Avalanche Forecast

Issued: Apr 26th, 2014 4:00PM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Storm Slabs and Deep Persistent Slabs.

a.l. horton, Parks Canada

Jasper.

It is important to monitor the weather while on your trip. The avalanche hazard will rise with prolonged exposure to direct sunlight.

Summary

Weather Forecast

Snowy conditions will continue through to Sunday morning with 10 cm possible. Light Easterly winds will shift to SW. Temps will remain cool with the freezing level only rising to 1700 m on Sunday. Cloudy cool conditions with some flurries through to Monday. Sun and warm temperatures will begin on Tuesday.

Snowpack Summary

Very little new snow from predicted storm. There is rain crust from the valley bottom to 2,350m and a sun crust into Alpine on solar aspects. Settled wind slabs are on NE aspects from 2,000 m to the alpine. Moist and wet snow exists below the crust extending into the alpine on solar aspects. The mid-pack is solid on North aspects. Large cornices.

Avalanche Summary

No field trips today. On April 23rd, avalanche control produced size 1-2 soft slabs at 2200m sliding on a rain crust and cornice failures produced size 3's on steep un-skiable terrain (Cromwell and Boundary peak).

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Sunday

Problems

Storm Slabs

Slabs that formed on the April 22 crust have not been reactive lately. It is still possible to trigger these slabs on steep terrain below ridgelines or convex features.

Avoid lee and cross-loaded terrain near ridge crests.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

Large triggers such as cornice failures have the potential to initiate deep avalanches. Depending on aspect, could be a wet or dry slab characteristic.

Pay attention to overhead hazards like cornices.Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Apr 27th, 2014 4:00PM