Avalanche Forecast

Issued: Feb 16th, 2014 8:05AM

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

Avalanche Canada rbuhler, Avalanche Canada

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

A strong west to southwesterly flow continues to drive a series of moist systems across the interior regions. The next frontal system will cross the interior on Sunday night and most of Monday resulting in more precipitation and wind. The second system is expected Tuesday overnight. Wednesday is expected to be mainly dry with periods of sun.Sun. Night/Monday: Snowfall 8-12cm, freezing level rising to 1300m in the afternoon, ridgetop winds 30-40km/h SW easing in the afternoon.Tuesday: Snowfall beginning in the afternoon and overnight 10-15cm, freezing level rising to 1300m in the afternoon, ridgetop winds 20-40km/h SW increasing overnight.Wednesday: Mostly dry, cloudy with sunny breaks, afternoon freezing level around 500m, ridgetop winds 40-60km/h W-NW easing in the afternoon.

Avalanche Summary

A widespread natural avalanche cycle has been occurring across the forecast area over the last few days with natural and human-triggered avalanches up to size 3.5. These avalanches are occurring on all aspects and elevation bands.On Saturday, an avalanche fatality occurred near Revelstoke. Details are still limited but here is a media report.

Snowpack Summary

Snowfall amounts have varied across the forecast region, but up to 100cm+ of storm snow is settling into a cohesive slab which is now typically 50-80cm thick. This slab is sitting on the weak Feb 9 interface which consists of multiple layers of surface hoar, faceted snow, and/or crusts from the past few weeks of cold clear weather. Reports indicate very easy snowpack tests results and widespread large destructive avalanche activity. Due to the persistent nature of these buried weaknesses, touchy conditions are likely to exist for some time.Strong ridge top winds have created wind slabs on leeward features at treeline and above. These wind slabs are the primary concern for the near future and strong forecast winds over the next few days are expected to add to this problem.For the most part, the mid and lower snowpack are strong and well consolidated.

Problems

Storm Slabs

An icon showing Storm Slabs
Snowfall over the last week is settling into a storm slab (typically 50-80cm thick) above the weak Feb.10th surface hoar/facet/crust interface. Stiffer wind slabs also exist in leeward features in wind exposed areas.
Use caution in lee areas in the alpine and treeline. Recent wind loading have created wind slabs.>Expect heavy trailbreaking until the storm snow settles out.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Valid until: Feb 17th, 2014 2:00PM

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