Archived

Avalanche Forecast

Apr 7th, 2015–Apr 8th, 2015

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

1: Low

The avalanche danger rating at treeline will be low

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

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

1: Low

The avalanche danger rating in the alpine will be low

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Coast.

Sunshine are warmth are the primary drivers of avalanche hazard. Avoid sun exposed slopes in the afternoon, and stick to higher, shady aspects for the best snow.

Confidence

Good - The weather pattern is stable

Weather Forecast

Wednesday: Mainly sunny. The freezing level climbs to around 2000 m during the day and drops below 1500 m overnight. Winds are light and variable. Thursday: Mainly sunny. The freezing level climbs to around 2000 m during the day and drops below 1500 m overnight. Winds are light and variable. Friday: Cloudy with light to moderate snow. The freezing level lowers to 1500 m and winds increase to moderate or strong from the S-SW.

Avalanche Summary

Moist loose avalanches have been reported on steep sun-exposed slopes, and one natural cornice fall (size 2) was reported on Monday. This cornice did not trigger a slab on the slope below.

Snowpack Summary

On shady slopes, 20-30 cm of low density storm snow sits on a strong and supportive rain crust that was buried last Saturday and extends as high as 2100m. Previous west-southwesterly winds have created thin new wind slabs in lee terrain, especially high N aspects. Expect an ongoing melt-freeze cycle on sun-exposed slopes. A facet/crust layer that was buried in mid-March is now approximately 50-100 cm down. Recently it was found down 55 cm near the Duffey Lake Road, and produced moderate sudden results. This remains a concern in the region because of it's potential for very large avalanches. Cornices are now large and mature and may collapse with daytime warming and intense sunshine.

Avalanche Problems

Persistent Slabs

A couple persistent weak layers are still present in the upper snowpack. These have not been reactive for a few days now, but intense spring sun or cornice falls could be enough to reawaken this problem.

Be aware of thin areas that may propogate to deeper instabilites.>Avoid convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 5

Loose Wet

Expect loose wet activity on steep sun-exposed slopes during the day.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Minimize exposure to sun exposed slopes when the solar radiation is strong.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Cornices

Daytime warming and sunshine could weaken large overhanging cornices and cause them to fail. These are a hazard alone, but also a potential trigger for deeper weak layers.

Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 4