Avalanche Forecast

Issued: Apr 16th, 2018 4:29PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Loose Wet.

mconlan, Avalanche Canada

Kootenay Boundary.

More snow is expected on Tuesday. Observe for the bond of the new snow to the previous surfaces before committing into avalanche terrain. Be particularly cautious under periods of rapid snowfall loading, as avalanche activity will likely increase.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

TUESDAY: Cloudy with snowfall, accumulation 10 to 20 cm, light to moderate west winds, alpine temperature -3 C, freezing level 1500 m.WEDNESDAY: Mostly sunny and afternoon clouds, light southeast winds, alpine temperature -3 C, freezing level 1500 m.THURSDAY: Mostly sunny, light southwest winds, alpine temperature 0 C, freezing level 2000 m.

Avalanche Summary

On Sunday, many loose wet avalanches and storm slab avalanches were triggered naturally and by explosives.Â They were large (size 2 to 2.5) and on all aspects between 1700 m and 2100 m.Â

Snowpack Summary

Around 20 to 30 cm of snow fell on Monday.Â This fell on moist snow or a melt-freeze crust up to at least 1800 m produced from rain and warm temperatures on Sunday. Â Numerous other melt-freeze crusts exist in the upper snowpack from rain, sun, and warming during the spring season. The snowpack below this is generally well-settled and strong.At lower elevations below treeline, a spring snowpack exists.

Problems

Storm Slabs

20 to 30 cm of snow fell on Monday, producing slabs that may not bond well to previous surfaces, including wet snow at low elevations, a crust at higher elevations, and wind slabs near ridge tops. More snow on Tuesday will make the slabs touchier.

Observe for the bond of new snow with the old surface before committing into avalanche terrain.Avoid avalanche terrain under periods of rapid snowfall or wind-transport loading.Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Loose Wet

Precipitation will fall as rain at low elevations. The snow will rapidly weaken and could slide easily with the weight of a human, producing large avalanches.

Avoid steep slopes when air temperatures are warm or when it is raining.Use caution above cliffs and terrain traps where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Apr 17th, 2018 2:00PM