Avalanche Forecast

Issued: Apr 7th, 2018 4:05PM

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

jmcbride, Avalanche Canada

South Rockies.

New snow, strong winds and rising freezing levels are increasing avalanche danger for the forecast period. Choose conservative terrain and be especially wary of overhead hazards as the day warms or the sun shines.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

TONIGHT: Cloudy, flurries. Accumulation 10-15 cm. Ridge wind strong, west. Alpine temperature near -7. Freezing level 500 m.SUNDAY: Cloudy, flurries. Accumulation 2-6 cm. Ridge wind moderate to strong, west. Alpine temperature near -3. Freezing level 1800 m.MONDAY: Mostly sunny. Ridge wind moderate, west. Alpine temperature near 0. Freezing level 2100 m.TUESDAY: Increasing cloud. Ridge wind moderate to strong, southwest. Alpine temperature near +4. Freezing level 2600 m.

Avalanche Summary

On Friday both natural and easily skier-triggered wind slab releases up to size 1.5 were reported in the southern part of the region, while several loose dry avalanches were reported in the Crowsnest Pass area. Read recent MIN report here. Thursday in the Elkford area, recent small (size 1) loose/dry avalanches were reported on northerly aspects while loose/wet were observed on solar aspects. In the southeast corner of the region skier-triggered loose/dry avalanches were reported to be running far on a recently buried crust.Wednesday small loose wet point releases were reported from steep rocky solar aspects.On Tuesday, small avalanches were observed in the Alexander Creek area. On Monday, small natural avalanches were reported from the region, and ski cutting produced similar small avalanches on wind-loaded features. Also on Monday, explosives triggered one size 2 wind slab avalanche on an east aspect at 2300 m. This avalanche ran on a 60 cm deep crust layer.

Snowpack Summary

10-15 cm of snow sits above a variety of crusts on all but high north aspects. Northern parts of the region have less new snow than southern parts. Wind has formed hard slabs in lee features, and in some cases the snow may be poorly bonded to the crusts.Multiple crusts exist in the top metre of the snowpack. Some parts of the region may have a surface hoar layer roughly 60 cm deep on north aspects at treeline.A well settled midpack sits above sugary facets in many parts of the region, especially thin snowpack areas.

Problems

Storm Slabs

New snow and strong winds will form storm slabs at all elevations. Expect these slabs to be touchy especially as freezing levels begin to rise following the storm. Watch for moist or wet snow releases at lower elevations and on sunny slopes.

Use caution in wind-loaded, lee areas in the alpine and treeline. Storm snow will form touchy slabs.Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Cornices

Cornices are reported to be large and there have been recent observations of cornice releases.

Give cornices a wide berth when travelling on or below ridges.Cornices may become weak with rising freezing levels.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Apr 8th, 2018 2:00PM