Archived

Avalanche Forecast

Apr 9th, 2019–Apr 10th, 2019

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

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.

Where the sun comes the surface snow will moisten quickly and increase the potential of loose wet avalanches.

Confidence

High -

Weather Forecast

TUESDAY NIGHT: Mainly cloudy with flurries / moderate northerly wind / freezing level at 1500 mWEDNESDAY: Mix of sun and cloud with scattered flurries / light to moderate northwest wind / alpine high temperature -2 C / freezing level 1900 mTHURSDAY: Mainly cloudy / 5 cm accumulation overnight / light southwest wind / alpine high temperature -5 C / freezing level 1700 mFRIDAY: Mix of sun and cloud / trace of snow / light north wind / alpine high temperature -4 C / freezing level 1900 m

Avalanche Summary

On Monday, only a few human triggered loose wet avalanches to size 1 were reported.On Sunday, there were reports of numerous natural, human and explosive triggered storm slab avalanches up to size 2.5 at treeline and in the alpine on all aspects (see this MIN report).On Saturday, explosives triggered small (size 1-1.5) storm slab avalanches up to 30 cm deep. Skier traffic triggered small pockets of storm snow with the deepest (up to 40 cm) and most reactive deposits in specific lee terrain.

Snowpack Summary

10-35 cm of recent storm snow that fell over the weekend sits on a melt-freeze crust on most aspects and is bonding well with the underlying layer. On north facing slopes above 2000 m, where the recent new snow sits on dry snow and surface hoar (feathery crystals) it is not bonding as well and might be sensitive to triggering. Recent snowfall amounts taper quickly below treeline.

Avalanche Problems

Loose Wet

Warm temperatures and sun exposure will increase the potential for loose wet avalanches.

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

Wind Slabs

10-35 cm of recent storm snow is only slowly bonding with the underlying dry snow on north facing slopes above 2000 m. Moderate northerly winds might create shallow wind slabs in immediate lee features along ridge crests overnight and during the day.

Use caution on open slopes and convex rollsUse caution in lee areas and cross-loaded terrain near ridge crests.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 1.5