Archived

Avalanche Forecast

Mar 30th, 2017–Mar 31st, 2017

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

2: Moderate

The avalanche danger rating below treeline will be moderate

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

Regions: Kootenay Boundary.

Forecast warm weather and potential sunny periods Friday will keep the avalanche danger elevated at upper elevations

Confidence

Moderate - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

FRIDAY: Mix of sun and cloud / Light southwest wind / Alpine temperature -1 / Freezing level 1800mSATURDAY: Cloudy with sunny breaks and isolated flurries / Moderate southwest wind / Alpine temperature -2 / Freezing level 1700mSUNDAY: Mix of sun and cloud / Light to moderate northwest wind / Alpine temperature -5 / Freezing level 1400m

Avalanche Summary

On Wednesday there were reports of both natural and explosives controlled storm slab avalanches 20-40cm deep to size 2 on southerly and northwest aspects at tree line. One report detailed a size 2 remotely triggered avalanche running on the melt freeze crust formed by the March 21 warming event. This ran on an east aspect at 1900m and was 50cm deep. There were also reports of skier controlled avalanches at tree line to size 1.5 on east an north aspects.

Snowpack Summary

A series of snowfalls throughout the past week accumulated roughly 60-90 cm of new snow in the region. Periodic high freezing levels and solar exposure over the same period formed a variety crusts within the storm snow at both lower elevations and on solar aspects. This all overlies a rain crust that formed mid-March at all elevations. At upper elevations, above 2100m approximately, the late and mid-February persistent weak layers (100-150cm down) and basal facets in shallow snowpack areas may still exist.

Avalanche Problems

Storm Slabs

Recent snow accumulations and wind have developed reactive storm slabs in the alpine and at tree line.

Be increasingly cautious as you transition into wind affected terrain.Be alert to conditions that change with aspect and elevation.New snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Loose Wet

Warm spring days with high daytime freezing levels and potential sun may continue to result in loose wet avalanches on all aspects.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2