Avalanche Forecast

Issued: Apr 15th, 2018 4:07PM

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 Monday. 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 - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

MONDAY: Cloudy with snowfall, accumulation 10 to 15 cm, light to moderate southwest winds, alpine temperature -5 C, freezing level 1200 m.TUESDAY: Cloudy with light snowfall, accumulation 5 to 15 cm, light to moderate west winds, alpine temperature -3 C, freezing level 1500 m.WEDNESDAY: A mix of sun and clouds, light southeast winds, alpine temperature -3 C, freezing level 1500 m.

Avalanche Summary

On Saturday, small storm slab and loose wet avalanches were reactive to skier traffic within the recent storm snow. The storm slabs were at treeline and alpine elevations, 15 to 45 cm deep, and often in lee terrain features. The loose wet avalanches were generally at below treeline elevations.

Snowpack Summary

Wind slabs may linger in lee alpine terrain features, which were produced from strong south winds. Rain to at least 1800 m produced wet snow on all aspects, which will freeze into a melt-freeze crust at higher elevations. New snow will fall on these surfaces. Numerous other melt-freeze crusts exist in the upper snowpack from rain, sun, and warming over the past month. The snowpack below this is generally well-settled and strong.At lower elevations below treeline, a spring snowpack exists.

Problems

Storm Slabs

Monday's snow will fall on saturated snow at low elevations, a crust at higher elevations, and wind slabs near ridge tops. The new snow may not bond well to these surfaces.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Loose Wet

Precipitation could fall as rain at low elevations. The upper snowpack is already saturated from the weekend's rain and could slide easily with the weight of a human.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Apr 16th, 2018 2:00PM