Avalanche Forecast

Issued: Apr 9th, 2018 4:10PM

The alpine rating is high, 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.

Warm air and rain are forecasted for Tuesday. This warming will weaken the snow surface and increase the likelihood of triggering avalanches. Travel in avalanche terrain is not recommended at high elevations and make sure to avoid overhead exposure.

Summary

Confidence

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

Weather Forecast

TUESDAY: Cloudy with light precipitation, accumulation 5 to 10 mm water equivalent, light to moderate southwest winds, alpine temperature 2 C, freezing level 3000 m dropping to 2000 m over the day.WEDNESDAY: A mix of sun and cloud, light south winds, alpine temperature -2 C, freezing level 1700 m.THURSDAY: Cloudy with snowfall, accumulation 5 to 10 cm, light southwest winds, alpine temperature -3 C, freezing level 1500 m.

Avalanche Summary

Storm slabs from the weekend's storm snow were reactive to humans, explosives, and natural triggers on Sunday. The slabs were small to large (size 1.5 to 2.5), 20 to 30 cm deep, generally on east to south to southwest aspects, and from 1700 to 2200 m.Loose wet avalanches were also reactive. A natural cycle occurred in the south of the region on Sunday, with small to large (size 1.5 to 2.5) avalanches on all aspects up to 2050 m.

Snowpack Summary

Warm air temperatures have moistened the snow surface at all elevations and on all aspects. Forecasted snow on Tuesday will fall on this. Around 20 to 40 cm of storm snow that fell on the weekend with associated strong winds overlies numerous melt-freeze crusts formed over the past few weeks.The mid and lower snowpack is generally well-settled and strong.

Problems

Storm Slabs

Warm air is expected well above the mountain tops, which will weaken storm slabs that formed over the weekend. Natural and human triggering will become more likely because of this.

Observe for the bond of new snow with the old surface before committing into avalanche terrain.It is a good day to avoid avalanche terrain due to the likelihood of triggering avalanches.Avoid overhead exposure, as avalanches may run full-path.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 3

Loose Wet

Recent wet avalanches have been large and destructive. Be cautious if you find moist or wet snow, which may be found to the mountain tops on Tuesday. Watch out in steep and gullied terrain, where even small avalanches can have severe consequences.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Valid until: Apr 10th, 2018 2:00PM