Avalanche Forecast
Issued: Apr 3rd, 2018 5:00PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Intensity of incoming weather systems is uncertain on Thursday
Weather Forecast
Only small amounts of snow on Thursday-Friday. Temperatures stay cool for this time of year.WEDNESDAY: Mainly cloudy with occasional flurries (up to 5 cm) / Moderate south west wind / Alpine temperature -4 / Freezing level 500m rising to 1400m in the afternoon THURSDAY: (Wet) flurries (5-10 cm) or rain at lower elevations / Light to moderate south-west wind / Alpine temperature -3 / Freezing level 1400mFRIDAY: Isolated flurries (5 cm possible) or rain at lower elevations / Moderate south west wind / Alpine temperature -4 / Freezing level 1300m.
Avalanche Summary
On Tuesday, natural avalanche activity was tapering, but human triggered avalanches to size 1.5 were still reported, failing on melt-freeze crusts on sunny aspects, or buried surface hoar on northerly aspects. 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!!! Since then, only 2-4 cm of new snow has fallen, and temperatures stayed cool. 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
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 4th, 2018 2:00PM