Archived

Avalanche Forecast

Apr 20th, 2018–Apr 21st, 2018

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

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

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

3: Considerable

The avalanche danger rating below treeline will be considerable

Regions: Kootenay Boundary.

Wintery conditions up high - spring conditions down low. Watch for conditions that change with elevation.

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Saturday

Weather Forecast

Saturday: 8-15cm of new snow / Strong southwest winds / Freezing level at 1800mSunday: Clear skies / Light and variable winds / Freezing level at 1900mMonday: Clear skies / Light and variable winds / Freezing level at 2400m

Avalanche Summary

No new avalanches have been reported. I would expect expect a new round of wind slab activity on Saturday in response to new snow and wind. Loose wet avalanches and cornice falls will soon become problematic with warming and solar radiation forecast for Sunday and Monday.

Snowpack Summary

New snow and wind on Saturday are expected to form new wind slabs in upper elevation lee terrain. Depending on aspect and elevation, the new snow will likely overlie moist snow, a melt-freeze crust or settled storm snow from earlier in the week.Numerous other melt-freeze crusts exist in the upper snowpack from rain, sun, and warming during the spring season. The mid and lower snowpack are generally well-settled and strong while melt-freeze conditions exist on all aspects below treeline.

Avalanche Problems

Wind Slabs

New snow and wind will promote new wind slab development in upper elevation lee terrain. Watch for triggering behind ridge crests and in gullies.

Be cautious as you transition into wind affected terrain.Stay off recent wind loaded areas until the slope has had a chance to stabilize.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

Loose Wet

Rain at lower elevations will promote ongoing loose wet avalanche activity. Use increased caution in steep open terrain below treeline.

Use caution above cliffs and terrain traps where small avalanches may have severe consequences.Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 1.5