Avalanche Forecast

Issued: Apr 21st, 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 and Cornices.

Avalanche Canada zryan, Avalanche Canada

Carefully assess steep lines for wind slab and limit exposure to slopes with cornices above. 

Summary

Confidence

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

Weather Forecast

THURSDAY NIGHT: High cloud increasing. Light westerly winds. Freezing level remains elevated at around 1300 m.

FRIDAY: Increasing cloud cover with light flurries in the afternoon. Light southwesterly winds. Freezing level remaining steady at 1400 m. Treeline temperatures around -1 C.

SATURDAY: Cloudy with snowfall, 5-10 cm of accumulation. Moderate to strong southerly winds. Freezing level around 1400 m. Treeline temperatures around -2 C.

SUNDAY: Cloudy with flurries, up to 5 cm of accumulation. Moderate to strong southwesterly winds. Freezing level 1000 m. Treeline temperatures around -4 C.

Avalanche Summary

A small skier-triggered wind slab was reported near Terrace on Wednesday (size 1). This avalanche occurred on a convex roll in the alpine and failed on slick melt-freeze crust. 

A few natural wind slab releases were observed in the Bear Pass area on Tuesday afternoon. These reached size 2 (large) and were limited to steep, wind-loaded features in the alpine. 

Looking forward to Friday, small but reactive wind slabs may exist in lee features in the alpine. Winds have varied in direction, so watch for wind slabs on all aspects.

Snowpack Summary

5-15 cm of new snow buried heavily wind-affected surfaces in open areas, the product of strong outflow wind early last week. In open areas, this new snow has been redistributed by easterly winds into small pockets of wind slab in lee areas. A crust will likely be found on steep solar aspects from warm temperatures and sun yesterday. Below 1200 m, a more widespread crust exists at or near the surface. Above 1200 m, 40 to 80 cm of settled storm snow is well bonded to another hard melt-freeze crust from late March.

Terrain and Travel

  • Carefully evaluate steep lines for wind slabs.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Wind Slabs

An icon showing Wind Slabs

5-15 cm of new snow and shifting winds may have formed small pockets of wind slabs on a range of aspects in exposed areas. 

Use caution entering steep, lee terrain features below ridges. The snow could slide easily where it rests on a hard melt-freeze crust.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices are large this time of year and were likely weakened by recent cold temperatures. Exposure to cornices should be minimized, especially during periods of warm temperatures or strong sun. Give them a wide berth when you are travelling on ridge lines and avoid overhead exposure to large cornices. 

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3.5

Valid until: Apr 22nd, 2022 4:00PM

Login