Avalanche Forecast

Issued: Apr 8th, 2018 4:08PM

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

jmcbride, Avalanche Canada

Lizard-Flathead.

New snow and rising freezing levels means elevated avalanche danger for the next few days. Choose conservative terrain and be especially wary of overhead hazards as the day warms or the sun shines.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TONIGHT: Cloudy, flurries. Accumulation trace. Ridge wind moderate to strong, southwest. Alpine temperature near -0. Freezing level 1600 m.MONDAY: Mix of sun and cloud. Ridge wind moderate to strong, west. Alpine temperature near 0. Freezing level 2000 m.TUESDAY: Mostly cloudy. Ridge wind moderate to strong, southwest. Alpine temperature near +4. Freezing level 2600 m.WEDNESDAY: Mostly sunny. Ridge wind moderate to strong, southwest. Alpine temperature near 0. Freezing level 2000 m.

Avalanche Summary

Widespread storm slab and loose wet avalanche activity up to size 2.5 was reported on Sunday following Saturday's storm.Â 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

25 cm of new snow means about 40-50 cm of recent snow sits above a variety of crusts on all but high north aspects. Wind has formed isolated slabs in lee features, and in some cases snow may be poorly bonded to buried crusts.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. 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

Storm Slabs

New snow and wind have formed storm slabs at all elevations. Expect these slabs to be touchy as freezing levels begin to rise. Watch for moist or wet snow releases at lower elevations and on sun exposed slopes; these could trigger deeper slabs.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Use extra caution in wind-loaded, lee areas in the alpine and treeline. Storm snow will form slabs.Avoid sun exposed slopes when the solar radiation is strong, especially if 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 sun exposure. A cornice failure has the potential to trigger large avalanches on the slopes below.

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

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1.5 - 3

Valid until: Apr 9th, 2018 2:00PM