Avalanche Forecast

Issued: Apr 14th, 2018 5:21PM

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

jsmith, Avalanche Canada

Northwest Coastal.

Rising temperatures and sunny skies on Sunday will likely trigger loose wet avalanches on steep slopes facing the sun.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

SUNDAY: Mostly sunny. Light northeasterly ridgetop winds. Alpine temperature +2. Freezing level rising to around 1400 m.MONDAY: Mostly sunny. Light northeasterly ridgetop winds. Alpine temperature 0. Freezing level around 1200 m.TUESDAY: Mostly cloudy with sunny breaks. Light southwesterly ridgetop winds. Alpine temperature -1. Freezing level around 1100 m.

Avalanche Summary

No new avalanches were reported in this region on Friday. On Wednesday, a size 2.5 persistent slab avalanche was remotely triggered by a group of skiers on a ridgetop from 10 m away. The avalanche failed on surface hoar about 70 cm deep on a north aspect at 1800 m. A size 2 wet slab was triggered by day-time warming in the same area near Bear Pass.

Snowpack Summary

10-20 cm of recent storm snow and strong variable winds have formed wind slabs on a variety of aspects at treeline and above.In the south of the region, two layers of surface hoar are buried approximately 70-100 cm deep. The layers are most prominent on north to east aspects and were buried early-March and mid-March. In the north of the region, these layers are around 40 cm deep.Bellow these March layers the mid-pack is generally well-settled and strong. However, shallower parts of the region, such as the far north, have weak sugary facets near the bottom of the snowpack.

Problems

Loose Wet

When the sun comes out it will quickly weaken the new snow and cause loose wet avalanching on steep solar slopes.

Minimize exposure to sun exposed slopes when the solar radiation is strong.Watch for signs that the snow is heating up such as pin-wheeling or the surface snow becoming moist.Cornices become weak with daytime heating. Give them a wide berth both from above and below.

Aspects: North, North East, East, South East, South, South West.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Sunshine may cause recently formed wind slabs to become more reactive to human triggers.

Avoid areas that look freshly loaded with snow; especially convex features below ridgetops.Travel on ridgetops to avoid wind loaded slopes.Use caution when transitioning into wind effected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 15th, 2018 2:00PM