Avalanche Forecast

Issued: Apr 9th, 2018 4:33PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Loose Wet and Cornices.

jmcbride, Avalanche Canada

South Rockies.

The warming trend and elevated avalanche danger continues for a few more days. Choose conservative terrain and be especially wary of overhead hazards as the day heats up or if the sun shines.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TONIGHT: Mostly clear. Ridge wind moderate to strong, west. Alpine temperature near 0. Freezing level 2200 m.TUESDAY: Mostly cloudy. Ridge wind moderate to strong, southwest. Alpine temperature near +4. Freezing level 2600 m.WEDNESDAY: Mostly sunny. Ridge wind light to moderate, west. Alpine temperature near 0. Freezing level 2000 m.THURSDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind light to moderate, south. Alpine temperature near -2. Freezing level 1200 m.

Avalanche Summary

On Sunday several loose wet, natural and skier triggered avalanches up to size 2 were reported, as well as storm slabs up to size 1.5 with natural, skier and explosive triggers.Last week, 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. And on 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.

Snowpack Summary

Rising freezing levels have caused the recent 10-15 cm of storm snow to become moist up to about 2000 m. Below 1400 m in some areas, rain has soaked the snow surface.Multiple crusts exist within the top 100 cm 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

Loose Wet

Rising freezing levels and daytime warming have been triggers for recent large, loose wet snow releases. Once moving, a loose, wet release may have the potential to trigger a slab on a deeper weak layer.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Cornices

Cornices are reported to be large and may become weak with rising freezing levels and/or sun exposure. A cornice failure has the potential to trigger large avalanches on the slopes below.

Minimize exposure to overhead hazard from cornices.Give cornices a wide berth when travelling on or below ridges.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Apr 10th, 2018 2:00PM