Avalanche Forecast

Issued: Apr 9th, 2019 3:38PM

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

dsaly, Avalanche Canada

South Coast Inland.

Wind has developed slabs around ridges and in lee features at upper elevations. If the sun comes out and temperatures rise, the likelihood of loose wet avalanches will increase as the snowpack warms, especially in areas with fresh snow.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

TUESDAY NIGHT: Mostly cloudy with isolated flurries / west wind, 10-20 km/h / alpine low temperature -6 C / freezing level 1200 mWEDNESDAY: Cloudy with isolated flurries, trace to 5 cm snow / southwest wind, 15 gusting to 45 km/h / alpine high temperature -4 C / freezing level 1600 mTHURSDAY: Cloudy with flurries, 5-15 cm / southwest wind 10-30 km/h / alpine high temperature -3 C / freezing level 1800 mFRIDAY: Cloudy with sunny periods, flurries near the Coquihalla, up to 10 cm / southwest wind 10-15 km/h / alpine high temperature 0 C / freezing level 1900 m

Avalanche Summary

A MIN report from the Whistler Backcountry here documents a skier triggered slab avalanche on a north-northeast alpine aspect on Monday. The avalanche was triggered in lee-ward terrain below a ridge feature. While outside the forecast region, the avalanche highlights a similar terrain feature that may hold wind slabs in the South Coast Inland.A natural avalanche cycle to size 2 likely occurred overnight Saturday around the Duffey; slab avalanches to size 2 were observed on north-northeasterly aspects around ridgetops and in recently loaded lee features on Sunday. Explosives also triggered small (size 1-1.5) wind slab avalanches on north to west aspects about 2000 m.On Saturday, small wind slab pockets were reactive to skiers in cross-loaded features at treeline.The likelihood of triggering loose wet avalanches will increase on if the sun shines, especially in areas with fresh snow.

Snowpack Summary

Up to 20 cm wind and temperature affected snow covers a melt-freeze crust on most slopes, and dry, faceted snow and isolated surface hoar on north-facing alpine terrain. Wind slabs have formed around ridgetops and lee alpine features. Warm temperatures during the day are moistening the snowpack up to 2000 m; snow is rapidly melting at lower elevations. With spring conditions, the avalanche hazard will fluctuate greatly depending on the strength of the overnight freeze and how quickly the snowpack is warmed up each day.

Problems

Wind Slabs

Wind has redistributed recent snowfall at upper treeline and alpine elevations. Use caution around lee terrain features and steep, convex slopes.

Expect conditions to change with elevation.Be careful with wind-loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Loose Wet

The recent snow will moisten quickly on southerly aspects when the clouds clear. Loose wet avalanches can become dangerous quickly, so use added caution when the sun is out.

Minimize exposure to cornices as they can weaken with daytime heating.Use extra caution on slopes if the snow is moist or wet.Avoid sun-exposed slopes and overhead exposure during periods of intense sun.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Apr 10th, 2019 2:00PM