Avalanche Canada jsmith, Avalanche Canada

South Coast Inland Avalanche Forecast

Apr 11th, 2019 5:47PM

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.

Any appearance of the strong April sun can initiate a loose wet avalanche cycle. The likelihood of loose wet avalanches increases as temperatures warm through the day and/or if the sun comes out for a prolonged period of time.

Summary

Confidence

High -

Weather Forecast

THURSDAY NIGHT: Cloudy / Light, northwesterly winds / Alpine low -4 C / Freezing level 1000 m.FRIDAY: Mix of sun and cloud / Light, westerly winds / Alpine high -2 C / Freezing level 1700 m.SATURDAY: Snow; 5-15 cm. / Moderate, southwesterly winds / Alpine high -2 C / Freezing level 1600 m.SUNDAY: Cloudy with isolated flurries; 0-3 cm. / Light, westerly winds / Alpine high -4 C / Freezing level 1400 m.

Avalanche Summary

No new avalanches were reported in this region on Wednesday.A MIN report from Blowdown here documents a size 2 skier triggered wind slab avalanche on a northeast alpine aspect on Monday.A MIN report from the Whistler Backcountry here documents a similar skier triggered slab avalanche on Monday. The avalanche was triggered  on a northwesterly aspect in lee terrain below a ridge feature. While outside the forecast region, the avalanche highlights the wind slab problem that exists in the South Coast Inland.

Snowpack Summary

10-20 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 upper treeline and alpine ridge crests and lee terrain 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

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1 - 1.5
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.

Loose Wet

An icon showing Loose Wet

Likelihood

Possible

Expected Size

1 - 1.5
Wet flurries, rain and rising temperatures can all warm the snowpack and increase the likelihood for loose wet avalanches, especially in areas with fresh snow.
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.

Valid until: Apr 12th, 2019 2:00PM