Avalanche Forecast

Issued: Apr 7th, 2018 3:41PM

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

mconlan, Avalanche Canada

South Coast.

A substantial amount of precipitation has fallen, with rain at lower elevations and snow at high elevations. Expect slabs where snow fell and loose, weak snow where rain fell.

Summary

Confidence

Moderate -

Weather Forecast

SUNDAY: Mostly cloudy with early-morning precipitation, accumulation 10 to 20 mm water equivalent, light westerly winds, treeline temperature 1 C, freezing level 1500 m.MONDAY: Mostly cloudy, light southerly winds, treeline temperature 1 C, freezing level 1500 m rising to 2200 m by the late afternoon.TUESDAY: Mostly cloudy with afternoon precipitation, accumulation 10 mm, treeline temperature 4 C, freezing level 2600 m dropping to 2000 m.

Avalanche Summary

On Thursday and Friday, it was easy to initiate large wet loose avalanche in steep terrain below treeline.Â The avalanches were generally slow but ran far.

Snowpack Summary

Around 30 to 80 mm of rain fell on the snowpack up to around treeline between Thursday and Saturday, with precipitation as snow above. In alpine terrain, the snow has created new storm slabs. This snow overlies a thick crust in most areas except for possibly shady aspects in alpine terrain. The snowpack below the crust is generally strong.At treeline and below treeline elevations, a spring snowpack exists. Rain saturated and weakened the upper snowpack.Â The wet snow may freeze overnight at higher elevations with cool temperatures.Â The mid and lower snowpack are strong.

Problems

Storm Slabs

Snowfall at higher elevations has formed new slabs. Observe for the bond of new snow with the old surface before committing into avalanche terrain.

Pay attention to overhead hazards like cornices, which could trigger slabs on slopes below.Use ridges or ribs to avoid pockets of wind-loaded snow.Observe for signs of instability, such as cracking and avalanche activity.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

More rain early Sunday morning will continue to weaken the upper snowpack. Watch out in steep and gullied terrain, where small avalanches can build and have severe consequences.

Use caution above cliffs and terrain traps where small avalanches may have severe consequences.Use extra caution on slopes if the snow is moist or wet.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Apr 8th, 2018 2:00PM