Avalanche Forecast

Issued: Jan 16th, 2018 4:47PM

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

jmcbride, Avalanche Canada

South Coast Inland.

A storm system approaches late Wednesday bringing snow and rain. Where snow has fallen new storm slabs may be touchy particularly on wind-loaded slopes. Wet snow releases will be possible in areas where the snowpack has been soaked by rain.

Summary

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

TUESDAY NIGHT: Light flurries. Accumulation trace. Ridge wind strong, southwest. Temperature -5. Freezing level 1000 m.WEDNESDAY: Cloudy, mix of rain and snow. Precipitation 20-30 mm. Ridge wind strong, south. Temperature near 0. Freezing level rising to 1800 m. (Rain is expected for southern areas, northern areas may see 20 cm of snow).THURSDAY: Cloudy, snow. Accumulation 10-15 cm. Ridge wind strong, southwest. Temperature -1. Freezing level 1300 m.FRIDAY: Cloudy, flurries. Accumulation 1-5 cm. Ridge wind light, southwest. Temperature -3. Freezing level 1000 m.

Avalanche Summary

On Sunday there was a report of a skier triggered size 2.5 slab avalanche in the northern part of the region that initiated as a 30 cm thick wind slab then stepped down to approximately 70 cm thick (likely the mid December layer) on a north-east aspect at 2050 m.

Snowpack Summary

A dusting of new snow has buried the most recent, January 15th crust. This crust exists on almost all aspects and elevations with the exception of northerly aspects above 1850 m where the snow surface remained dry during the alpine inversion event on the weekend.Below the January 15th crust about 30-50 cm of snow overlies a 1 cm thick crust that was buried on January 6th which exists up to about 2000m. Mid and lower snowpack layers including the mid December and late November crust layers have produced moderate to hard, sudden results in snowpack tests in the northern part of the region last week and may be a concern for step-down potential.

Problems

Storm Slabs

Loading from new snow and strong winds will build storm slabs on leeward aspects and exposed treeline areas near ridge crests. In northern parts of the region it may still be possible for a surface release to step down to a deeper layer.

Minimize exposure during periods of heavy loading from new snow and wind or rain.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Loose Wet

It may be possible to trigger a loose wet slide in steep, unsupported or convex terrain where rain has soaked the upper snowpack.

Use extra caution on solar slopes or if the snow is moist or wet.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 17th, 2018 2:00PM