Avalanche Forecast

Issued: Feb 1st, 2018 4:14PM

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

Avalanche Canada shorton, Avalanche Canada

Heavy accumulations are possible as an Arctic front sits over the region. Be prepared to dial back your terrain choices.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

FRIDAY: Flurries with accumulations of 5-10 cm / strong west wind / alpine temperatures around -12 C.SATURDAY: Another 5-15 cm of snow / moderate to strong west wind / alpine temperatures around -12 C.SUNDAY: Another 15-30 cm of snow / moderate to strong west wind / alpine temperatures around -10 C.

Avalanche Summary

On Wednesday, evidence of recent natural activity was reported in various parts of the region. Activity included storm slabs up to size 2 on all aspects and dry loose avalanches in steep terrain. On Tuesday, a small storm slab (size 1.5) was triggered by a skier on a southwest aspect at 1250 m. Some persistent slab activity has been reported on the December weak layer over the past few days as well. Several naturally-triggered size 2 persistent slab avalanches failed naturally at 1200 m in the Howsons on Tuesday. A large naturally-triggered size 3 persistent slab avalanche was reported on an east aspect at 1900 m in the Howsons on Monday. Two large remotely triggered avalanches (size 2.5) were reported on north and west aspects around 1600 m north of Kispiox late last week.

Snowpack Summary

Strong winds have built wind slabs in exposed terrain. 30-60 cm of snow lies over a crust and/or weak feathery surface hoar layer buried in mid-January. The crust exists well into the alpine and the surface hoar can be found in sheltered areas in the lower alpine and treeline elevations. Another two crust / surface hoar layers that formed in December are buried 50-80 cm below the surface. These layers produced sudden results in recent snowpack tests and have been the suspected weak layer in recent large remotely (from a distance) triggered avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and wind will form fresh wind slabs in higher elevation lee terrain.
Be cautious as you transition into wind affected terrain.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Watch for whumpfing, hollow sounds, and shooting cracks.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Persistent Slabs

An icon showing Persistent Slabs
Weak layers buried 30-80 cm below the surface have produced some recent avalanches, particularly on unsupported features.
Evaluate unsupported slopes critically.Avoid shallow or thick to thin snowpack areas where triggering a deeper layer is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 2.5

Valid until: Feb 2nd, 2018 2:00PM

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