Archived

Avalanche Forecast

Apr 15th, 2019–Apr 16th, 2019

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

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

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.

Be wary of sunny alpine slopes, the likelihood of triggering loose wet avalanches will increase as temperatures rise through the day. Reactive pockets of fresh snow may lurk around ridges and lee terrain on alpine slopes where snow remains dry.

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

MONDAY NIGHT: Mostly clear / west wind, 10 km/h / alpine low -2 C / freezing level valley bottomTUESDAY: Mix of sun and cloud with isolated flurries / southwest wind, 20-40 km/h / alpine high +3 C / freezing level 2100 mWEDNESDAY: Cloudy with sunny breaks / west wind, 25 gusting to 50 km/h / alpine high +3 C / freezing level 2300 mTHURSDAY: Rain and wet flurries, 5-15 mm / southwest wind, 30 gusting to 50 km/h / alpine high +5 C / freezing level 2700 m

Avalanche Summary

On Sunday, several small size 1 wind slabs were reactive to explosives, one size 3 wind slab avalanche was triggered with a very large explosive. Near Whitewater a skier triggered a windslab avalanche on a steep northwest aspect in the alpine. See the MIN report here.

Snowpack Summary

15-40 cm fell around the region since Saturday with flurries continuing through Monday. The new snow accumulated over a melt freeze crust on most aspects. On north-facing terrain above 2000 m, the new snow accumulated over another 15-30 cm wind-affected snow from early April. The snowpack is well settled below and snow is disappearing rapidly below treeline.Sun and rising freezing levels are warming the snowpack and settling new snow, the likelihood of loose wet avalanches will increase as heat penetrates into the snowpack.

Avalanche Problems

Loose Wet

Warm temperatures and sun will increase the likelihood of loose wet avalanches, especially where fresh snow has accumulated.

Use extra caution on slopes if the snow is moist or wet.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Minimize overhead exposure to cornices above.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2

Storm Slabs

Fresh snow has accumulated at upper elevations. Older wind slabs may be hidden under the fresh snow. Be cautious around ridge crests and in wind loaded terrain where deposits will be deepest.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be alert to conditions that change with elevation.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 1.5