Avalanche Forecast

Issued: Jan 21st, 2015 7:59AM

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

Peter, Avalanche Canada

Northwest Coastal.

Continued stormy weather will maintain elevated avalanche danger this week.

Summary

Confidence

Good

Weather Forecast

Synopsis: We could see a short lull in the weather on Thursday before another strong frontal system hits the North Coast on Friday. Expect 10-20 cm (mm) tonight and Thursday followed by 30-45 cm (mm) on Friday. The freezing level should be between 1400-1800 m and winds are strong from the southwest. Saturday looks like another lull in intensity but we could still see 15-20 cm with a freezing level a couple hundred metres lower.

Avalanche Summary

Heavy snow or rain, and strong upper winds are probably producing a widespread natural avalanche cycle throughout the region. Expect wet activity below treeline and the potential for large storm slabs and isolated deep slabs from higher terrain. This pattern should continue for most of the week.

Snowpack Summary

Heavy snowfall (with rain below 1000 m) and strong southwest winds will build deep and dense storm/wind slabs throughout the week. The slab will likely be 'upside down' with warming temperatures dropping moist or dense snow on previous dry lower-density snow. A buried rain crust and/or surface hoar layer is down about 60-80 cm. Observations of the strength at this interface have been limited. The November crust near the bottom of the snowpack is generally well bonded, but may 'wake up' with intense loading this week. There is potential for isolated very large and deep avalanches.

Problems

Storm Slabs

Heavy loading from snow and wind could tip off a natural avalanche cycle at and above treeline, especially from wind loaded slopes (N to E facing).

Be alert to conditions that change with elevation.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

2 - 6

Wet Slabs

We could see significant rain below around 1500 m. Expect wet avalanche activity in all steep terrain below treeline.

Avoid slopes with glide cracks.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 5

Valid until: Jan 22nd, 2015 2:00PM