Avalanche Forecast

Issued: Nov 23rd, 2012 4:03PM

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

max darrah, Parks Canada

Jasper.

More new snow brings the 72 hour total to around 40cm in the Parker Ridge area. Expect drifting on the highway and wind slab formation above treeline.

Summary

Weather Forecast

Partly cloudy skies with light scattered snowfall for the weekend, possibly clearing towards the afternoon on Sunday. Temps to stay mild, with predominant winds light westerly. Freezing levels to remain below 1000m.

Snowpack Summary

5-10cm of new snow brings the total snowfall to 45cm since Nov 20.Two separate wind events (Nov21 M-NW and Nov23 M-SE) suggest wind slab formation on a variety of aspects in the alpine and at exposed areas at treeline. Lots of snow still available for transport.

Avalanche Summary

Numerous natural size 1-3 observed in the last 48 hours on a variety of aspects in the alpine, mostly on cross loaded gully features. Lots of sluffing from steep rocky terrain.

Confidence

Forecast snowfall amounts are uncertain on Friday

Problems

Wind Slabs

Numerous natural slab avalanches have been observed in the past 48hrs, mostly in wind loaded features above 2300m. These slides occurred on a range of aspects due to the shifting winds and loading pattern in the past 72 hours.

Avoid travelling in areas that have been reverse loaded by winds.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

Previous wind slabs can be found buried beneath the recent storm snow on lee aspects in exposed terrain.

The recent snow may now be hiding windslabs that were easily visible before the snow fell.Be careful with wind loaded pockets while approaching and climbing ice routes.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Nov 24th, 2012 4:00PM