Avalanche Forecast

Issued: Apr 16th, 2018 4:13PM

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

mbender, Avalanche Canada

Northwest Coastal.

The weather is due to change with snowfall forecast for Wednesday and Thursday. Avalanche danger will gradually increase as the snow starts to accumulate Thursday.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

TUESDAY: Mix of sun and cloud. Light southwest wind. Alpine temperature -2. Freezing level 1100 m. WEDNESDAY: Flurries, accumulation 5-10cm. Light to moderate south wind. Alpine temperature -2. Freezing level 1100 m. THURSDAY: Periods of snow, accumulation 10-20cm. Moderate south wind. Alpine temperature -1. Freezing level 1200 m.

Avalanche Summary

Reports from this weekend indicate loose wet activity on steep slopes facing the sun at tree line and in the alpine. These avalanches were reported as size 1-2 and were isolated to the recent surface snow only. Several naturally triggered wind slabs up to size 2 on steep alpine features were reported near Bear Pass on Saturday.

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 early-March and mid-March are approximately 70-100 cm deep. The layers are most prominent on north to east aspects and were buried 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, in the portions of the region with a shallower snowpack, 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

Possible

Expected Size

1 - 2

Wind Slabs

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

Travel on ridgetops to avoid wind loaded slopes.Use caution when transitioning into wind effected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Apr 17th, 2018 2:00PM