Avalanche Forecast

Issued: Mar 25th, 2022 4:00PM

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

Avalanche Canada wlewis, Avalanche Canada

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Watch for new and old wind slabs at higher elevations. Light snowfall over the day may form fresh and reactive slabs on a crust. 

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

FRIDAY NIGHT: Mostly cloudy with flurries. Moderate southerly winds and freezing levels drop to 1000 m.

SATURDAY: Mostly cloudy. 10-15 cm is possible in terrain north of the Jervis Inlet and Clendinning Provincial Park. Elsewhere 5 cm is possible over the day. Freezing levels around 1500 m. Moderate southerly winds.

SUNDAY: Mostly cloudy with 10-30 cm of snow. Freezing levels around 1500 m. Moderate to strong southerly winds. 

MONDAY: Another 10-15 cm possible overnight. Clearing during the day with flurries. Light northeast winds. Freezing levels reach 1800 m.

Avalanche Summary

Warm temperatures, rain and sun on Tuesday, Wednesday and Thursday produced large wet avalanches on all aspects below the freezing line, and on steep sun affected slopes. 

Human and naturally triggered cornice falls were also reported over the week, with the last reported cornice to trigger a slab avalanche on the slope below occurring on Monday. Cornices may remain weak and reactive to human triggers. 

A large avalanche was reported on a steep alpine slope near Blackcomb on Thursday, likely failing on the mid February weak layer, now buried around 80 cm deep. While the trigger is unknown, it's likely that strong sun had weakened the snowpack. 

Snowpack Summary

Light snow will fall on a melt freeze crust that extends into the alpine on all aspects to 2000-2500 m and on south facing slopes to mountain top. On shaded aspects new snow will sit over wind affected surfaces. 

40 to 90 cm overlies the mid March interfaces. This layer exists as surface hoar in shady, wind-sheltered areas and a hard crust on sun-exposed slopes into the alpine. Several other weak layers exist in the upper and mid snowpack, reports suggest these layers are bonding well and avalanche activity is unlikely except from large loads like cornice falls. 

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Wind slabs are most reactive during their formation.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

Fresh and reactive wind slabs are expected to form over a crust on north and east facing slopes. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 26th, 2022 4:00PM