Avalanche Forecast

Issued: Dec 5th, 2017 4:00PM

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

garth lemke, Parks Canada

Jasper.

Good skiing exists in sheltered areas near treeline. Thursday may have freezing levels rising to 3400m which is unusual for this time of year. Expect the danger to increase with unseasonably warm temperatures.

Summary

Weather Forecast

Wednesday will be mainly sunny, no new snow, high of 1 degree, 10-20km/hr NW winds, and 2100m freezing level. Thursday will be sunny, alpine temperature of 4 degrees, light NW winds, and 3400m freezing level. This spike in freezing level is unusual for this time year. Friday will be sunny, light West winds, and 2200m freezing level.

Snowpack Summary

Wind slabs are in exposed lee features. A significant crust (Black Friday, Nov.23) can be found down 30 to 70cms. A persistent slab overlays this crust and so far the bond appears to be strengthening at this interface. The Halloween crust sits well down in the snowpack at TL locations and as high as 2700m.

Avalanche Summary

No patrol on Tuesday and nothing new reported. No new avalanches noted on Monday.

Confidence

The weather pattern is stable on Wednesday

Problems

Wind Slabs

Wind slabs are present on lee aspects. Bond strength of these slabs to the snowpack below is uncertain.

Use caution in lee areas. Recent wind loading has created wind slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 6th, 2017 4:00PM