Avalanche Forecast

Issued: Apr 17th, 2022 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

Last weeks's torrent of outflow wind didn't leave behind much loose snow to transport. This means Monday's resurgence in wind probably won't increase avalanche danger.

Be sure to check out the newest forecaster blog as you plan your spring objectives.

Summary

Confidence

High -

Weather Forecast

SUNDAY NIGHT: Clear. Light south winds shifting east and increasing.

MONDAY: Becoming cloudy with light flurries beginning in the afternoon with a trace of new snow. Moderate to strong east winds. Treeline high temperatures around -2.

TUESDAY: Mainly cloudy with 5-10 cm of new snow from overnight. Light to moderate east winds, increasing over the day. Treeline high temperatures around -3.

WEDNESDAY: Clearing with another 5cm of new snow from the overnight period. Light east winds. Treeline high temperatures around 0.

Avalanche Summary

No new avalanches were reported on Friday, however a few new and recent cornice releases were observed, failing to trigger slabs on slopes below. Saturday's reports included observations of an older natural size 3 (very large) wind slab as well as pinwheeling and minor point releases from steep solar terrain.

On Thursday, explosives triggered wind slabs size 1-2 on south-southeast aspects. A skier triggered a size 1 wind slab on a northwest aspect at 1700 m. Additionally, a vary large (size 3.5) natural cornice failure triggered a deep slab on the steep slope below which ran full path. On Wednesday in the north of the region, several natural wind slabs (size 1.5-2) were observed in the alpine as a result of strong outflow winds loading west-facing aspects. One natural cornice failure was also observed (size 2.5) that did not pull a slab on the slope below.

Numerous natural wind slabs (size 2-3) were observed in the alpine on Monday and Tuesday as a result of northeasterly outflow winds. Wind slabs may still exist in lee areas in the alpine and exposed treeline. Riders should minimize overhead exposure to cornices and give them a wide berth when travelling at ridge crest. 

Snowpack Summary

Open terrain has been affected by strong outflow wind that scoured east-facing slopes and loaded snow onto west-facing slopes early last week. Sheltered areas may still have soft snow. Below 1200 m, a widespread crust exists on the surface. Above 1200 m, 40 to 80 cm of settled storm snow rests on a hard melt-freeze crust from late March. The snow has been bonding to this crust.

Terrain and Travel

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Problems

Cornices

An icon showing Cornices

Cornices are large this time of year and may have been 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

Wind Slabs

An icon showing Wind Slabs

Last week's outflow winds left slabs on west and south-facing slopes in the alpine and near ridgetops at treeline. Although most of these will have stabilized by now, steep, loaded features near ridgecrests should still be treated with caution.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Apr 18th, 2022 4:00PM