Avalanche Forecast

Issued: Nov 23rd, 2019 3:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

Avalanche Canada cgarritty, Avalanche Canada

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Venture cautiously as you investigate the outcome of the storm. Use this forecast as an initial assessment and gather information as you travel. Remember to post your observations to the Mountain Information Network!

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

Saturday night: Easing flurries bringing an uncertain 5-15 cm of new snow. Strong northwest winds.

Sunday: Mainly cloudy with isolated flurries with a trace to 5 cm of new snow. Moderate northwest winds. Alpine high temperatures around -7.

Monday: Mainly cloudy. Light to moderate west winds. Alpine high temperatures around -8.

Tuesday: Mainly cloudy. Light to moderate northeast winds. Alpine high temperatures around -10.

Avalanche Summary

For this weekend, the focus is on new snow that has buried the previous snow surface. This new snow is expected to shed easily as sufficient depths accumulate to form new slabs. Strong winds are expected to accelerate this accumulation as well as slab formation. 

Any new wind slabs formed by Sunday morning are expected to be primed for human triggering. Concern is reduced in areas where the new snow hasn't yet overcome the depth of ground roughness.

Snowpack Summary

Moderate new snow amounts have begun to accumulate in the region, with 25 to 30 cm of new snow expected by the end of the storm Saturday night. 

Observations in the region are limited, but we have indications that for most areas where previous snow cover existed, the new snow has buried a supportive melt-freeze crust. Above 1800 metres it may add to a patchy cover of windblown snow in lee areas and windloaded pockets.

The new snow is not expected to bond well to either of these surfaces.

Total snow depths of 30-40 cm were reported prior to the storm at alpine elevations in the Smithers area, with depths diminishing rapidly with elevation below 1500 metres.

Problems

Wind Slabs

An icon showing Wind Slabs

Saturday's new snow is likely to have been blown into touchy new wind slabs at higher elevations. These slabs are unlikely to form a solid bond with the previous surface over the near term.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Nov 24th, 2019 5:00PM

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