Avalanche Forecast

Issued: Feb 2nd, 2019 4:00PM

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

stephen holeczi, Parks Canada

Banff Yoho Kootenay.

Great ski quality in sheltered areas. Give the new snow time to settle before committing to bigger terrain features with consequence.

Summary

Weather Forecast

Frigid arctic air will win the battle for the weekend with temperatures down to -30C for the weekend and highs below -20C. Winds will diminish as we switch to an E/NE flow with no snow in the immediate forecast.

Snowpack Summary

25-40cm of new snow with moderate to strong variable winds. Up to 65cm sits over the Jan.17 surface hoar which has been found up to 2300m. The mid-pack is quite dense above the Dec 10 interface down 80-160 cm. In shallower areas weak facets and depth hoar exist below the Dec 10 interface. In deeper snowpack this basal weaknesses is less pronounced

Avalanche Summary

Local ski hills reported avalanches up to size 2 within the storm snow. No other avalanches were observed or reported with limited visibility.

Confidence

Problems

Storm Slabs

25-40cm of new snow has fallen under warmer temperatures at all elevations which will be reactive in the short term. The Jan. 17th layer is buried up to 65cm deep and consists of surface hoar, facets or crust and can be found up to 2300m.

Use caution in lee areas in the alpine and treeline. Storm snow is forming reactive slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

The new snow load may start waking up the deep persistent facet weakness down 80-160 cm. This is of greatest concern in shallow snowpack areas where the basal facets are weakest.

Avoid thin, rocky or unsupported slopes.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Feb 3rd, 2019 4:00PM