Avalanche Forecast

Issued: Jan 19th, 2018 4:38PM

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

jmcbride, Avalanche Canada

South Coast.

Friday was a day of rapid change and increasing avalanche hazard due to intense snowfall and windloading. This trend will continue with wind and heavy snow expected for the weekend. Stick to simple terrain until the new snow has had time to settle.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

TONIGHT: Snow. Accumulation 10-15 cm. Ridge wind moderate, southwest. Temperature -2. Freezing level 800 m.SATURDAY: Snow. Accumulation 25-35 cm. Ridge wind moderate, southwest. Temperature -1. Freezing level 800 m.SUNDAY: Heavy snow. Accumulation 30-50 cm. Ridge wind strong, southwest. Temperature -1. Freezing level 900 m.MONDAY: Snow. Accumulation 5-15 cm. Ridge wind moderate, southwest. Temperature -1. Freezing level 800 m.

Avalanche Summary

On Friday ski cutting produced size 1, storm snow releases on a south-facing, wind loaded feature at treeline. Rapid loading and significant cornice development were also reported on Friday with professionals in the region commenting that conditions were changing dramatically during the day, and avalanche hazard increasing.

Snowpack Summary

Above 1000m about 30 cm of new snow has fallen with as much as 50-60 cm of new snow at higher elevations. This storm snow now covers the January 17th crust and is being redistributed by wind at upper elevations. Below 1000 m, rain has soaked the upper snowpack which consists of 90 cm of wet to moist snow and three deeper crusts (January 10th, January 8th and January 7th). These remain visible but have been unreactive in recent snowpack tests. The snowpack depth at 1000 m is about 160 cm and many early season hazards are still present.

Problems

Storm Slabs

Recent storm snow and strong southerly winds have formed reactive storm slabs, particularly on lee slopes at upper treeline and alpine elevations. These slabs overlie a recent melt-freeze crust and may be easily triggered by a skier or rider.

Minimize overhead exposure during periods of heavy loading from new snow, wind.Use careful route-finding and stick to moderate slope angles with low consequencesWhumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Jan 20th, 2018 2:00PM