Avalanche Forecast

Issued: Feb 12th, 2015 4:31PM

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

a.l. horton, Parks Canada

Jasper.

A special public avalanche warning will be issued for the Jasper area this weekend. Avalanche control is planned on the Icefields Parkway on Friday. Expect delays in the afternoon.

Summary

Weather Forecast

Freezing levels around 2000 m with no overnight freeze expected Thursday and Friday nights. A brief pulse of precipitation is expected on Friday with temperatures falling with the passage of the front on Saturday afternoon.

Snowpack Summary

There is a wide variation in the snowpack across the forecast region. Continuing moderate to strong SW winds in the Icefields area are forming wind slabs on lee slopes. Last week's snow is now a persistent slab 50-80 cm thick. This slab is sitting over the Jan 29 rain crust on all aspects at treeline and above.

Avalanche Summary

Two size 2 slab avalanches were observed around treeline today on low angle northerly aspects. It is likely that these avalanches failed on a surface hoar layer sitting on the January 30 rain crust.

Confidence

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

Problems

Persistent Slabs

These slabs are sitting on a surface hoar layer in sheltered areas. Triggering of these slabs is possible even in low angle terrain .

Use caution in lee areas in the alpine and treeline. Recent storm snow has formed touchy slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Deep Persistent Slabs

This layer remains a concern in isolated areas above treeline and may be triggered by large loads.

Avoid steep slopes below cornices.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 13th, 2015 4:00PM