Avalanche Forecast

Issued: Apr 13th, 2019 5:06PM

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

jsmith, Avalanche Canada

Sea To Sky.

Light amounts of new snow and extreme southeasterly winds have grown cornices and formed small wind slabs that may be further below ridgecrests than expected.

Summary

Confidence

High -

Weather Forecast

SATURDAY NIGHT: Cloudy with flurries; 3-5 cm. / Moderate, westerly winds / Alpine low -5 C / Freezing level 900 m.SUNDAY: Cloudy with sunny periods and isolated flurries; 0-3 cm. / Light, southwesterly winds / Alpine high -3 C / Freezing level 1100 m.MONDAY: Mix of sun and cloud / Light, southwesterly winds / Alpine high -1 C / Freezing level 1200 m.TUESDAY: Mix of sun and cloud with flurries; 0-3 cm. / Light, southwesterly winds / Alpine high 0 C / Freezing level 1500 m.

Avalanche Summary

On Saturday small (size 1) storm slabs were reactive to skier traffic, primarily in lee terrain below ridgetops.On Monday, four skier-triggered storm slab avalanches (size 1.5-2) in the Whistler backcountry were reported on north facing aspects below alpine ridgetops, including this Decker Main MIN report here.

Snowpack Summary

Currently, the snowpack structure changes dramatically with elevation and aspect. Light amounts of new snow and extreme southeasterly winds on Saturday scoured windward surfaces and may have created fresh wind slabs much further down slopes than expected. These winds also created cornice growth. Expect these new cornices to be fragile.Below roughly 1900 m, the snowpack is moist and is melting rapidly at lower elevations. Check out this useful link for managing avalanche hazard during spring conditions HERE.

Problems

Wind Slabs

Light amounts of new snow and extreme winds have formed fresh wind slabs that may be further below ridgecrests than expected.

Use small slopes without consequence to test the bond of the new snow.Pay attention to changing conditions with elevation/aspect.Avoid wind loaded slopes below ridgetops.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Loose Wet

Any appearance of the strong April sun can initiate a loose wet avalanche cycle.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Apr 14th, 2019 2:00PM