Archived

Avalanche Forecast

Apr 15th, 2019–Apr 16th, 2019

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

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

1: Low

The avalanche danger rating below treeline will be low

Regions: North Columbia.

Be cautious of reactive deposits of new snow around ridges and in lee terrain. If the sun shines or the snowpack turns moist, the likelihood of triggering loose wet avalanches will increase, especially in areas with fresh snow.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

MONDAY NIGHT: Mostly clear / southwest wind, 10-15 km/h / alpine low -5 C / freezing level valley bottomTUESDAY: Cloudy with sunny breaks and isolated flurries, trace accumulation / southwest wind, 25-35 km/h / alpine high 0 C / freezing level 1800 mWEDNESDAY: Cloudy with scattered flurries, up to 5 cm accumulation / southwest wind, 25-35 gusting to 50 km/h / alpine high 0 C / freezing level 2100 mTHURSDAY: Cloudy with scattered wet flurries, up to 10 cm / southwest wind, 25-45 km/h / alpine high +2 C / freezing level 2300 m

Avalanche Summary

On Sunday, two size 2 storm slab avalanches were triggered by skiers on east aspects at 2200m. A group of skiers remote triggered a size 2 storm slab avalanche from 50 m away, failing on a southeast slope at 2250 m. One natural size 2 storm slab avalanche was observed on a steep, north aspect between 2100-2550 m. Late Saturday, storm snow was sloughing in steep terrain with skier traffic and gaining cohesion.

Snowpack Summary

15-40 cm fell around the region since Saturday, in the alpine new snow has been redistributed by wind in exposed areas. The new snow accumulated over a melt freeze crust on most aspects. On north-facing terrain above 2000 m, the new snow accumulated over another 20-30 cm wind-affected snow from early April, in isolated areas surface hoar may now be buried 30-65 cm. Older wind slabs sitting on surface hoar might still be sensitive to human triggers. Below treeline snow is disappearing rapidly. Sun and rising freezing levels are warming the snowpack and settling new snow, the likelihood of loose wet avalanches will increase as heat penetrates into the snowpack.

Avalanche Problems

Loose Wet

If the sun comes out today or the snowpack moistens, the likelihood of loose wet avalanches will increase on sun exposed slopes.

Use extra caution on slopes if the snow is moist or wet.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Minimize overhead exposure to cornices above.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Storm Slabs

New snow is being redistributed by wind. Fresh snow may hide older, recently formed wind slabs. Be cautious around ridge crest and lee terrain where deposits of new snow will be most reactive.

Be alert to conditions that change with elevation.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 1.5