Archived

Avalanche Forecast

Apr 16th, 2014–Apr 17th, 2014

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: Kootenay Boundary.

This bulletin was created using very limited field data. If you are out in the mountains, please send your observations to [email protected]

Confidence

Poor - Due to the number of field observations

Weather Forecast

Tonight and Thursday: Light to moderate snow or rain 5 cm tonight, 10 -15 cm/mm Thursday. The freezing level is around 1800 m. Winds are moderate from the South. Friday: Cloudy with flurries or showers. The freezing level is around 1600-1800 m. Winds are light to moderate from the West. Saturday: A mix of sun and cloud. The freezing level rises to 2200 m and ridge winds are light to moderate from the south.

Avalanche Summary

No new avalanches were reported on Tuesday. There was one report of a size 2.5 natural deep persistent slab in the Rossland Range that occurred on Sunday afternoon in response to strong solar radiation and warm temperatures. This avalanche released on a steep southeast aspect at around 2100 m and likely failed on the mid February weak layer. It's a good reminder of the potential for large deep avalanches under certain conditions.

Snowpack Summary

A trace of new snow sits on a thick and solid melt-freeze crust in most places. This crust has been breaking down on all aspects up to around 2000 m and above this elevation on solar aspects most days. The late January/early February persistent weak layer is deeply buried and has not produced avalanches in this region for some time now. Cornices are large in some areas and should be given a wide berth.

Avalanche Problems

Wind Slabs

It may be possible to trigger fresh wind slabs in steep lee terrain, especially where the new snow overlies a hard crust.

Avoid freshly wind loaded features.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Deep Persistent Slabs

Rain, warming, and periods of sun could be enough to wake up a deeply buried persistent weak layer and produce a very large avalanche.

Be aware of the potential for large, deep avalanches due to the presence of buried persistent weak layers.>Use caution on big alpine slopes, especially around thin areas that may propagate to deeper instabilities.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 2 - 5