Avalanche Forecast

Issued: Apr 9th, 2015 9:08AM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Persistent Slabs, Loose Wet and Cornices.

bcorrigan, Avalanche Canada

South Coast.

The hazard may go higher than forecast if precipitation amounts are greater than expected.

Summary

Confidence

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

Weather Forecast

Friday: Increasing cloud with snow beginning late in the day. 10 cm of snow expected overnight with the freezing level coming down to 1200m by morning. Winds forecast moderate to strong from the S-SW. Saturday: Cloudy with snow flurries. The freezing level continues downward to around 1200-1400 m and winds are moderate from the SW.Sunday: Cloudy with flurries, freezing level around 1000m and winds light to moderate from the south.

Avalanche Summary

Moist loose avalanches have been reported on steep sun-exposed slopes, and one natural cornice fall (size 2) was reported earlier in the week, but didn't trigger a slab release on the slope below.

Snowpack Summary

On shady slopes, 15-25 cm of cold low-density snow sits on a strong and supportive rain crust that was buried last Saturday and extends as high as 2100m. Expect an ongoing melt-freeze cycle on sun-exposed slopes. A facet/crust layer that was buried in mid-March is now approximately 50-100 cm down. Recently it was found down 55 cm near the Duffey Lake Road, and produced moderate sudden results. This remains a concern in the region because of it's potential for very large avalanches. Cornices are now large and mature and may collapse with daytime warming and intense sunshine.

Problems

Persistent Slabs

There are two persistent weak layers still present in the upper snowpack. These have not been reactive for a few days now, but intense spring sun , a wind slab avalanche, or cornice fall could be enough to reawaken this problem.

Be aware of thin areas that may propogate to deeper instabilites.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Loose Wet

Expect loose wet activity on steep sun-exposed slopes during the day.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Minimize exposure to sun exposed slopes when the solar radiation is strong.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Daytime warming and sunshine could weaken large overhanging cornices and cause them to fail. These are a hazard alone, but also a potential trigger for deeper weak layers.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Apr 10th, 2015 2:00PM