Avalanche Forecast

Issued: Apr 9th, 2018 4:47PM

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

Lizard-Flathead.

The warming trend and elevated avalanche danger continue for the next few 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 light to moderate, southwest. Alpine temperature near 0. Freezing level 2200 m.TUESDAY: Mostly cloudy. Ridge wind moderate to strong, southwest. Alpine temperature near +4. Freezing level 2500 m.WEDNESDAY: Mostly sunny. Ridge wind moderate, southwest. Alpine temperature near 0. Freezing level 2000 m.THURSDAY: Cloudy, flurries. Accumulation 5-10 cm. Ridge wind light, southeast. Alpine temperature near -2. Freezing level 1400 m.

Avalanche Summary

On Monday there was a report of a natural size 2.5 loose, wet avalanche that failed overnight on a northeasterly aspect in the alpine and ran for 600 m.Widespread storm slab and loose wet avalanche activity up to size 2.5 was reported on Sunday following Saturday's storm. The new snow was reactive to skier and explosive triggers on all aspects above 1400 m. And one natural size 2.5 was reported on an easterly aspect at 1550 m.On Friday skier's reported a close call on wind-loaded slope on a southeast aspect at 1940 m. Read their MIN report here.Also on Friday, explosive control work produced wind slab and cornice releases up to size 2 in alpine terrain.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.

Snowpack Summary

Rising freezing levels have caused the recent 25 cm of storm snow to become moist up to ridge top elevations. Below 1400 m, rain has soaked the snow surface.There are some reports of a surface hoar layer roughly 100 cm deep on north aspects at treeline, but no recent avalanche activity on this layer. Below this, the mid-pack is generally well settled and strong.A layer of sugary facets around a crust exists near the bottom of the snowpack, but this layer has been inactive for some time.

Problems

Loose Wet

Rising freezing levels and daytime warming have been triggers for recent large, loose, wet avalanches. 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 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

1.5 - 3

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