Avalanche Forecast

Issued: Jan 27th, 2018 4:06PM

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

jsmith, Avalanche Canada

South Coast Inland.

Natural avalanche cycle expected on Sunday. Travel in Avalanche terrain is not recommended.

Summary

Confidence

High -

Weather Forecast

SUNDAY: 20-30 cm of new snow (rain below roughly 1200m) / Strong to extreme southwesterly ridgetop winds / Freezing level rising to around 1500m.MONDAY: 10-20 cm of new snow (rain below roughly 1500m) / Strong to extreme southwesterly ridgetop winds / Freezing level rising to around 1800m.TUESDAY: Cloudy with flurries; 3-5 cm / Strong southwesterly ridgetop winds / Freezing level dropping to around 700m.

Avalanche Summary

On Thursday, two natural storm slab avalanches stepped-down to facets at the bottom of the snowpack and resulted in 3-3.5 avalanches. They occurred on north and south aspects between 2000 and 2250 m. The extended period of continuous loading of the snowpack may begin to reactivate deeply buried weak layers resulting in large and destructive avalanches running full path.

Snowpack Summary

10 cm of new snow on Friday morning brings recent storm totals to 80-110cm. This weekend's storm will likely create dense storm slabs lurking in lee and cross-loaded features at treeline and above.90-120cm below the surface you'll likely find a few crusts that were buried during the first few weeks of January. Due to limited observations, not much is known about the current reactivity of these layers.The lower snowpack includes the mid-December crust layer. The load of the new snow may tip the balance and reactivate this layer in isolated terrain - particularly in the north of the region where it's shown prolonged reactivity in snowpack tests.

Problems

Storm Slabs

New snow and wind will create touchy storm slabs reactive to human triggers.

The new snow may require several days to settle and stabilize.Avoid avalanche terrain during periods of heavy loading from new snow and wind.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

Intense loading of new snow may awaken deeply buried weak layers resulting in large, destructive avalanches.

Be mindful that deep instabilities are still present and have produced recent large avalanches.Large triggers such as falling cornice or smaller avalanches may step-down to deeply buried crusts.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3.5

Cornices

Large amounts of new snow and high winds will create tinder cornices sensitive to human triggers.

Give cornices a wide berth when traveling on or below ridgesFalling cornices may trigger large avalanches on slopes below.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Valid until: Jan 28th, 2018 2:00PM