Avalanche Forecast

Issued: Feb 12th, 2013 9:54AM

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

jfloyer, Avalanche Canada

Northwest Coastal.

The recent storm was more intense than anticipated. Touchy, dangerous conditions will linger. Be cautious if you are venturing into the backcountry at this time.

Summary

Confidence

Fair - Intensity of incoming weather is uncertain

Weather Forecast

Synopsis: A short-lived ridge builds for Wednesday before a series of generally light precipitation bands move through Thursday and Friday.Wednesday: Mostly dry. Northwest winds around 40 km/h at ridgetop. Freezing level around 400m.Thursday: Light snowfall, 2-5cm. Southwest winds to 50 km/h at ridgetop. Freezing level 800m in the afternoon.Friday: Light or locally moderate snowfall, 5-10cm. Perhaps a little more towards the coast. Extreme southwest winds, gusting up to 90km/h at ridgetop.

Avalanche Summary

A widespread avalanche cycle up to size 3 was reported in response to the recent intense storm. The most activity appears to have been close to Terrace.

Snowpack Summary

A big dump of snow brought up to 80cm and an average of about 40cm new to the region on Tuesday. Strong winds have blown the new snow into wind slabs in exposed lee areas. The new snow sits on above previous wind slabs on shady slopes in the alpine and at treeline, and a rain/sun crust at lower elevations/solar aspects, respectively. Deeper buried crusts exist within the snowpack, but are reported to have bonded well. I imagine that after the most recent avalanche cycle, these will be difficult or near impossible to trigger, except with very big loads, such as a cornice fall. The mid and lower snowpack layers are generally well settled..

Problems

Storm Slabs

Rapid loading from new snow and winds has created very touchy slab avalanche conditions, especially in exposed areas.

Assess start zones carefully and use safe travel techniques.>Note recent avalanche activity.>Stay off recent wind loaded areas until the slope has had a chance to stabilize.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 6

Persistent Slabs

Various crust layers in the upper snowpack (location specific) still show sudden results and a propensity for propagation in snowpack tests. Local investigation to test distribution and reactivity is a good idea before committing to steep slopes.

Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Feb 13th, 2013 2:00PM