Archived

Avalanche Forecast

Apr 23rd, 2018–Apr 24th, 2018

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

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

Regions: South Coast Inland.

Sunshine and rising temperatures will elevate the avalanche danger throughout the week. Be aware of changing conditions throughout the day and avoid overhead hazards. This is our final daily forecast for the season which will expire on April 25th.

Confidence

Low - Due to the number of field observations

Weather Forecast

TUESDAY: Sunny. Light to moderate southwest wind. Alpine temperature +6. Freezing level 3000 m. WEDNESDAY: Sunny. Light northwest wind. Alpine temperature +9. Freezing level rapidly rising to 3500 m. THURSDAY: Sunny. Light west wind. Alpine temperature +11. Freezing level 3500 m.

Avalanche Summary

Avalanche reports have been limited due to very few information sources this time of year. If you have been out, please post your observations on the Mountain Information Network (MIN).

Snowpack Summary

A weak layer consisting of surface hoar, facets, and/or a melt-freeze crust from late March is now buried about 50 to 100 cm below the surface. This layer is spotty in its distribution; however, it has recently produced large and destructive avalanches. It is mostly likely to be problematic on west, north, and east aspects between 1900 m and 2250 m. I'd continue to treat this layer very cautiously and would anticipate increase reactivity on this layer with the warming forecast for the next few days.The mid and lower snowpack are well-settled and strong.

Avalanche Problems

Loose Wet

Warming and solar radiation are expected to trigger loose wet avalanches, especially in steep, sun-exposed terrain. Loose wet avalanches can be pushy and entrain mass quickly. Warming may also trigger destructive cornice failures.

Use extra caution on slopes if the snow is moist or wet.Avoid steep slopes when air temperatures are warm, or solar radiation is strong.Cornices become weak with daytime heating and sun exposure. Be aware of overhead hazard.

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

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2

Persistent Slabs

Professionals are traveling cautiously in shaded upper treeline and alpine terrain due to a weak layer buried 50 to 100 cm below the surface. Forecast warming and cornice failures may re-activate this layer in isolated terrain.

Avoid steep convexities or areas with a thin or variable snowpack.Be aware of the potential for wide propagation due to the presence of buried weak layers.Pay attention to overhead hazards like cornices, which could trigger persistent slabs.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3.5