Avalanche Forecast

Issued: Mar 30th, 2018 5:18PM

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

Avalanche Canada simonhorton, Avalanche Canada

Wind slabs at higher elevations are the main concern. The combination of fresh snow and clear skies will make the snow extra reactive on south-facing slopes.

Summary

Confidence

High - on Saturday

Weather Forecast

SATURDAY: Sunny with light wind, freezing level up to 900 m, and alpine high temperatures near -8 C.SUNDAY: Cloudy with flurries increasing throughout the day (10-20 cm of snow), light wind, freezing level up to 1200 m, and alpine high temperatures near -5 C.MONDAY: Mix of sun and cloud with light wind, freezing level up to 900 m, and alpine high temperatures near -8 C.

Avalanche Summary

Preliminary reports from Friday include a few small natural wind slabs in alpine terrain.On Thursday, numerous size 1-2 wind slabs were reported, including natural and explosive triggered avalanches on primarily east aspects in alpine terrain. A few size 1 skier triggered slabs on were reported on south aspects around 2300 m, including one that partially buried a skier.On Wednesday, we received reports of numerous natural storm slab avalanches up to size 3 in the alpine on all aspects, northwest of Radium as well as natural activity up to size 2.5 in areas west of Kimberley and Invermere. Several skier triggered wind slab and storm slab avalanches up to size 2.5 were also reported from all aspects above 2000 m. These results were predominantly failing on the recently buried late-March interface, with crown depths from 20-50 cm deep and up to 100 cm in some areas.

Snowpack Summary

Snowfall amounts have been variable over the past week, with areas just east of Kootenay Lake receiving up to 80 cm of snow while eastern parts of the region received 20-40 cm. The storm snow sits on an interface buried in late-March that consist of crusts below 1900 m and on south aspects, and surface hoar on shaded aspects at higher elevations. Other slightly deeper surface hoar/facet layers have been reported on shaded aspects at higher elevations and may be found approximately 40-60 cm below the surface.Deeper persistent weak layers from mid-late February as well as January and December layers, are still being monitored by professional observers, but are generally considered dormant. Facets also linger at the base of the snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind and fresh snow has formed wind slabs at higher elevations. Sunny aspects (south through west) require extra caution due to the presence of a buried sun crust, which is acting as an excellent sliding layer.
Pay attention to cornices, which may become weak when hit by the sun.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Use caution in lee areas. Recent wind loading has created wind slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Valid until: Mar 31st, 2018 2:00PM