Avalanche Forecast

Issued: Apr 8th, 2013 9:20AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada pmarshall, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

Synopsis: A frontal system will slide down the coast on Tuesday with precipitation beginning in the afternoon and continuing through Wednesday. A drying trend is expected on Wednesday and Thursday as a ridge of high pressure redevelops. Tuesday: Increasing cloud with precipitation beginning in the afternoon. Expect 5-10 mm late in the day. The freezing level is around 2000 m. Winds increase to moderate or strong from the southwest in the evening.  Wednesday: Moderate precipitation easing in the late afternoon – 15-25 mm. The freezing level drops from 2000 to 1500 m by the end of the system. Winds are strong from the southwest easing in the afternoon. Thursday: Mainly sunny. The freezing level is at 1000 m but solar radiation is strong so temperatures may feel warmer.  

Avalanche Summary

Several explosive or skier controlled slabs up to size 2 were reported on Sunday. Most of these events released on or just above the recently buried crust or moist snow.

Snowpack Summary

Recent snowfall amounts vary considerably with elevation due to fluctuating freezing levels. Some lee alpine areas may have accumulations over 50 cm. The new snow is sitting on a crust or moist snow depending on elevation. Dense new wind slabs are likely in exposed lee terrain at and above treeline. Most of the recent precipitation fell as rain or wet snow below 1700-1800 m. The upper snowpack at lower elevations has become isothermal from recent warm temperatures and rain. Cool overnight temperatures will likely form a new surface crust at lower elevations. Cornices are very large and could pop off with continued mild temperatures or during periods of sun.

Problems

Wind Slabs

An icon showing Wind Slabs
Dense wind slabs have formed in exposed terrain at higher elevations. Triggering is most likely on steep slopes below ridge crests or in cross-loaded gullies.
Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>The new snow will require several days to settle and stabilize.>

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Apr 9th, 2013 2:00PM