Avalanche Forecast

Issued: Mar 22nd, 2021 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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New snow and strong winds over the day Tuesday will likely form fresh, reactive wind slabs at upper elevations. In areas where less than 10 cm of new snow falls, avalanche hazard may be a step lower in the alpine.

Summary

Confidence

Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

Monday night: Cloudy with isolated flurries. Light to moderate westerly wind. Alpine temperature around -8. Freezing level valley bottom.

Tuesday: 10-20 cm of new snow in ranges north of Smithers, 5-10 cm in the south. Strong southwest winds. Alpine high temperatures around -4. Freezing level 1400 m.

Wednesday: 5-10 cm new snow. Light to moderate westerly wind. Alpine high temperatures around -5. Freezing level 1300 m.

Thursday: Mix of sun and cloud. Northwest wind increasing to strong. Alpine high temperatures around -7. Freezing level 1200 m.

Avalanche Summary

Reports of avalanche activity on Monday consisted of skier triggered size 1 loose dry out of steep terrain. Touchy storm slab conditions were observed on Saturday at Sinclair. Reactive wind slabs were reported in the Hudson Bay Mountain area on Friday prior to the storm.

Snowpack Summary

5-20 cm of new snow falls amid strong southwest wind. Near Smithers, 20-30 cm of snow from the past week (closer to 70-100 cm in the southwest) overlies hard wind affected snow at alpine elevations, potentially surface hoar crystals on sheltered north aspects, and melt-freeze crust on south aspects and below treeline. Recent observations suggest warm temperatures have aided bonding at this interface. At lower elevations, recently rain soaked, now refrozen and crusty surfaces are covered by a dusting of snow.

The mid and lower snowpack is reported as well settled and strong in most areas. However, weak facets exist at the base of the snowpack in the more shallow snowpack zones within much of the region and always have the potential of being triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs are most reactive during their formation.
  • Make observations and assess conditions continually as you travel.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Problems

Wind Slabs

An icon showing Wind Slabs

New snow and elevated southwest winds have formed new surface instabilities that vary by location in the region. Expect thicker, more widespread storm slab formation in the snowier southwest of the region and wind slabs more confined to leeward terrain at exposed elevations closer to Smithers.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 23rd, 2021 4:00PM