Avalanche Forecast

Issued: Apr 9th, 2019 3:41PM

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

Sea To Sky.

Flurries will accumulate through the day and may hide recently formed slabs. Use caution around ridge crests and lee terrain features, where the most reactive deposits may be found.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

TUESDAY NIGHT: Mostly cloudy / west wind, 15-30 km/h / alpine low temperature -6 C / freezing level 1000 mWEDNESDAY: Flurries, 5-10 cm snow / southwest wind, 20-40 km/h / alpine high temperature -4 C / freezing level 1400 mTHURSDAY: Sunny with cloudy periods and early morning flurries, trace to 5 cm / northeast wind, 15-35 km/h / alpine high temperature -2 C / freezing level 1500 mFRIDAY: Mix of sun and cloud / west-southwest wind 10-20 km/h / alpine high temperature -2 C / freezing level 1700 m

Avalanche Summary

On Monday, natural storm slab avalanches to size 2 were observed on north to northeast aspects around 2200-2400 m in the Whistler Backcountry, initiating from steep, lee start zones. 2 separate groups of skiers in the Whistler Backcountry triggered slab avalanches (size 1.5-2) on north-northeast aspects in the alpine, including this Decker Main MIN report here. On Sunday, avalanche control work with explosives triggered mostly small storm slabs (size 1-1.5) and cornices in alpine and treeline; these avalanches failed on the storm snow - melt-freeze crust interface.On Saturday, small (size 1-1.5) storm slabs and wind slabs were reactive to skier traffic. Cornices were reactive to explosives and triggered large (size 2) slab avalanches as they fell on the slopes below.

Snowpack Summary

Around 10 cm wind and temperature affected snow covers a melt-freeze crust on most slopes and dry, settled snow on north-facing and sheltered alpine terrain.Expect a snowpack that changes with elevation and through the day, between 1800 and 1200 m sun and warm temperatures through the day are producing a moist snowpack. Below, 1200 m the snow is melting rapidly.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

Recent snowfall, wind and continued flurries have formed slabs around ridge crests and into the alpine. Use caution around lee features and steep, convex slopes.

Expect conditions to change rapidly with elevation.Be careful with wind-loaded pockets, especially near ridge crests and roll-overs.Pay attention to overhead hazards like cornices.

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 if the clouds clear. Loose wet avalanches can become dangerous quickly, so use added caution when the sun is out.

Use extra caution on slopes if the snow is moist or wet.Avoid sun-exposed slopes and overhead exposure during periods of intense sun.Cornices become weak with daytime heating, so travel early on exposed slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

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