Archived

Avalanche Forecast

Mar 12th, 2015–Mar 13th, 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

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Kootenay Boundary.

Avalanche danger is rising in response to warm temps. On Friday, stay out of the sun, and over the weekend, avoid the rain!

Confidence

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

Weather Forecast

It is expected to be dry and very warm (freezing level 3000 m) on Friday. Around 15 mm precipitation is expected on Saturday, followed by about 15-25 mm on Sunday. The freezing level during the precip is around 2200 m, falling to 1900 m on Sunday (subject to change). Winds are moderate to strong from the SW.

Avalanche Summary

Apart from small loose wet sluffs triggered by skiers on steep sunny slopes, no new avalanches have been reported in the past several days.

Snowpack Summary

Available snow may shifted by SW winds at high elevations. Lower down the mountain, drizzle has weakened the snow surface layers, adding warmth and weight to the snowpack. The most prominent feature in the snowpack is the thick late-February crust, down 5-20 cm. Limited reports suggest this crust is supportive all the way to ridge crest, "capping" the snowpack and keeping riders from stressing any deeper weak layers. There are still weak layers bellow this crust. As temperatures become very warm over the next couple of days, be alert to whether this supportive capping layer is breaking down. Consequences go up if it does.

Avalanche Problems

Loose Wet

A hot sunny day is likely to further weaken rain-affected snow and may cause natural loose wet or wet slab avalanches.

Avoid steep or committing slopes if the snow is moist or wet.>Cornices become weak with heating, so avoid exposing yourself to them.>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: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 3

Wind Slabs

Strong winds may have shifted snow into wind slabs at high elevations.

Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 3