Avalanche Forecast

Issued: Feb 17th, 2014 8:25AM

The alpine rating is high, the treeline rating is considerable, 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

On Tuesday, the next Pacific frontal system tracks across the South Coast. The edge of this system should affect the southern portions of the NW regions. Generally unsettled conditions are expected for Wednesday before another weak system impacts the central coast on Wednesday night or Thursday morning.Tuesday: Snowfall 10-15cm in the south, 2-5cm in the north, afternoon freezing levels around 400m, ridgetop winds 40-60km/h SWWednesday: Mostly cloudy, light intermittent snowfall 1-3cm, afternoon freezing levels around 400m, ridgetop winds 20-30km/h SW-WThursday: Snowfall 5-10cm, afternoon freezing levels around 300m, ridgetop winds 30-50km/h W-NW

Avalanche Summary

On Sunday, natural slab avalanches up to size 2 were reported to be triggered by solar radiation. Two skier-triggered remote avalanches were reported (from 10-20m away), size 1.5 and 2, occurring down around 40cm with the storm snow overlying the Feb 10 weak layer.On Saturday, natural slab avalanches up to size 2 occurred, additionally some larger size 2.5 were triggered with explosives control. Numerous size 1-2 skier remote (up to 50 m away) slab avalanches released down 60 cm all on the old buried surfaces mentioned above in the snowpack summary.

Snowpack Summary

Over the past week the parts of the region have received over 1.5m of cumulative snowfall which has settled into a slab with a typical thickness of 60-90cm. This storm slab overlies a variety of facets, surface hoar, crusts, hard wind press, or any combination of these. Widespread whumpfing, cracking, avalanche activity and remote triggering at all elevations indicate there is a poor bond between the new snow and these old surfaces. Snowpack tests show easy, sudden planar results good propagation propensity.Recent Strong to extreme SE winds have built thick, touchy wind slabs on leeward terrain features and slopes.The mid and lower snowpack is generally strong and well-settled. Basal facets and depth hoar still sit dormant at the bottom of the snowpack in some parts of the region but triggering this layer is generally unlikely.

Problems

Storm Slabs

An icon showing Storm Slabs
60-90cm of recent snow has formed a reactive slab on all aspects and elevations, particularly on lee wind features. Remote triggering an avalanche from below or adjacent slopes remains a concern, and will likely catch you by surprise.
Use conservative route selection, stick to moderate angled terrain with low consequences even if skiing in the trees>Avoid wind loaded pockets, especially near ridge crests and roll-overs.>Stick to simple terrain and be aware of what is above you at all times.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Valid until: Feb 18th, 2014 2:00PM