Archived

Avalanche Forecast

Apr 15th, 2018–Apr 16th, 2018

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Northwest Coastal.

When the sun comes out it will quickly weaken the surface snow. Watch for signs that the snow is heating up such as pin-wheeling or the snow surface becoming moist.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

MONDAY: Mix of sun and cloud. Light northeasterly ridgetop winds. Alpine temperature +2. Freezing level around 1200 m.TUESDAY: Mostly cloudy with sunny breaks. Light southwesterly ridgetop winds. Alpine temperature +1. Freezing level around 1100 m.WEDNESDAY: Mostly cloudy with flurries. Light southwesterly ridgetop winds. Alpine temperature +2. Freezing level around 1200 m.

Avalanche Summary

Several naturally triggered wind slabs up to size 2 on steep alpine features were reported near Bear Pass on Saturday. 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 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.

Avalanche Problems

Loose Wet

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

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

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

Elevations: All elevations.

Likelihood: Possible - Likely

Expected Size: 1 - 2

Wind Slabs

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

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2