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Avalanche Forecast

Feb 27th, 2022–Feb 28th, 2022
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: South Columbia.

Stormy day ! Traveling in alpine terrain is NOT recommended. As avalanche hazard will increase throughout the day, choosing simple terrain is our best strategy.

Confidence

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.

Weather Forecast

A series of storms are set to hit the region in the next few days. Moderate to heavy snowfalls, rising freezing levels, and warmers temperatures are expected until mid-week. The west and north parts of the region will receive the heaviest amount of snowfalls.

Sunday night: Snow 5-10 cm overnight. Freezing level around 600 m. Alpine temperatures around -6 C. Moderate southwesterly winds gusting 50 km/h.

Monday: Snow 15-25 cm + 15-25 cm overnight. Freezing level rising to 1200 m. Alpine temperatures around -3 C. Moderate to strong southwesterly winds.

Tuesday: Snow 10-15 cm. Freezing level rising to 1600 m. Alpine temperatures 

around -2 C. Moderate to strong southwesterly winds.

Wednesday: Flurries up to 5 cm. Freezing level rising to 1400 m. Alpine temperatures around -4 C. Light to moderate southwesterly winds.

Avalanche Summary

A skier remotely triggered a large (size 2) wind slab near Keefer Lake on a north east facing cross-loaded feature at upper treeline. This avalanche was triggered from a distance, suggesting that persistent layers were involved. Few natural wind slabs also produced size 1.5-2 avalanches on Saturday.

In the Valhallas, a large persistent slab (size 2) was triggered by a skier on a northeast terrain feature at treeline. The avalanche picked up loose snow and ran for 400 m long. Few natural persistent slabs avalanches were reported to have failed on the mid-February weak layer/ crust combo.

With the current storm, avalanche activity will likely increase, and a natural cycle is expected late Monday / early Tuesday.

Snowpack Summary

10-20 cm of fresh snow has fallen Sunday throughout the region, with favoured amounts in the Monashees. This new snow is now burying a variety of surfaces including heavily wind-affected surfaces on most alpine slopes, fresh wind slabs on any open features, thin sun crust on steep south-facing slopes at all elevations, and widespread large feathery surface hoar crystal on sheltered areas. Below ~1200 m, 30-50 cm of snow is now overlying a thick melt-freeze crust. 

Two weak layers exist within the upper snowpack: the mid-February layer (down 70 to 120 cm) and the mid-January layer (down 100 cm). They both consist of surface hoar / melt-freeze crust. Although reactivity of these layers had tapered off lately, they should be treated with extra caution with this incoming series of snowfalls as they may produce large, unexpected avalanches.

Terrain and Travel

  • Travel in alpine terrain is not recommended.
  • Watch for fresh storm slabs building throughout the day.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.
  • Good day to make conservative terrain choices.

Avalanche Problems

Storm Slabs

Fresh storm slabs will build throughout the day. Their size and sensitivity will increase as the day progress. Use increased caution around treeline, where these slabs may overlay a weak layer, sun crust or hard wind slabs. Lee slopes, ridge crests and cross-loaded terrain are features of concern during a storm.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2

Persistent Slabs

Two weak layers exist within the upper snowpack: the mid-February layer (down 70 to 120 cm) and the mid-January layer (down 100 cm). They both consist of surface hoar / melt-freeze crust. Evidence of their reactivity has been observed consistently all week. With increased load from the current storm and warmer temperatures, they have the potential to "wake up" and produce large, unexpected avalanches. In times of uncertainty, choose simple terrain, low consequence slopes and conservative lines.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3.5