Archived

Avalanche Forecast

Apr 5th, 2015–Apr 6th, 2015

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

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

Regions: South Coast.

The hazard my go higher than forecast on solar aspects with daytime warming. Pay close attention to cornice features.

Confidence

Fair - Due to the number and quality of field observations

Weather Forecast

Possible 5 cm tonight, then a trace on Monday night as the remnants of a Pacific frontal system to the south move through the area. Sunny with cloudy periods for the remainder of the forecast period. Winds light generally from the south

Avalanche Summary

Moist loose avalanches reported on solar aspects below 1900m. No other reports from the area. Cornices are now becoming a concern as the Spring temps progress

Snowpack Summary

20-30 cm of low density storm snow is sitting on a strong and supportive rain crust that was buried last Saturday and extends as high as 2100m. West through southwesterly winds have shifted these new accumulations into touchy wind slabs in exposed lee terrain, especially high NE aspects. A facet/crust persistent weakness that was buried in mid-March is now approximately 50-100 cm down. In recent snowpack tests, it was found down 55 cm near the Duffey Lake Road and produced moderate sudden results. This remains a serious concern in the region because of it's potential for very large avalanches. Cornices are now large and mature and may collapse with warming and spring-like temperatures.

Avalanche Problems

Wind Slabs

Wind loaded features may produce an avalanche large enough to injure and bury a rider. There is also the potential for a small avalanche to trigger a deeply buried week layer.

Use ridges or ribs to avoid pockets of wind loaded snow.>Be alert to conditions that change with elevation.>The new snow will require several days to settle and stabilize.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 3

Persistent Slabs

The dense slab on this layer remains a concern. A small avalanche or a cornice failure might trigger this weakness and produce a large, destructive avalanche

Be aware of the potential for large, deep avalanches.>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: 3 - 5