Avalanche Forecast

Issued: Apr 2nd, 2018 5:03PM

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

Avalanche Canada mgrist, Avalanche Canada

The new snow will require time to settle in areas that saw more than 25cm of new snow (near Nelson and Kootenay Pass).Keep a close eye on how the new snow is bonding to the old surface below.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Unsettled weather until the next system arrives on Wednesday. Freezing levels will gradually increase towards the end of the week.TUESDAY: Cloudy with flurries (3-5 cm) / Light to moderate south west wind / Alpine temperature -7 / Freezing level 1200m WEDNESDAY: Cloudy with flurries (5-10 cm) / Moderate south west wind / Alpine temperature -5 / Freezing level 1000m THURSDAY: Lingering flurries (5 cm possible) / Light to moderate southwest wind / Alpine temperature -3 / Freezing level 1800m

Avalanche Summary

On Monday we received reports of widespread natural storm slab avalanches to size 1.5 on all aspects in Kootenay Pass. Crowns averaged 10-25cm thickness. On Friday, cornice control work resulted in triggering a size 2 wind slab below, on an east aspect near 2200m. Slab depth averaged 20cm.

Snowpack Summary

Well that was quite a storm, wasn't it Nelson? The region saw wildly variable amounts of new snow on Monday morning, ranging from 2cm to 48cm near Nelson!!!The new snow sits on firm crusts on sunny aspects, and all aspects below 1900m. On higher, shady aspects, the new snow may sit on some old wind slabs from last week, or a mix of large surface hoar and surface facets. Another weak layer buried mid March is down 50 to 120cm and is a crust on solar aspects and surface hoar (to 6mm) on high elevation north. A few other persistent weak layers are buried in the mid and lower snowpack, but they have gone dormant and are unlikely to resurface until we move into a period with consecutive above-freezing nights.

Problems

Storm Slabs

An icon showing Storm Slabs
Extra caution is advised where heavy snowfall sits on a firm melt-freeze crust... a perfect sliding layer for slab avalanches.
Be alert for dry loose sluffs: Pull over from time to time and let it go by on steeper pitches.Watch for areas with heavy snow fall accumulations... and be prepared to dial back terrain use.Check for how the new snow is bonding to the old surface below.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Apr 3rd, 2018 2:00PM

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