Avalanche Forecast

Issued: Feb 11th, 2018 4:47PM

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

pgoddard, Avalanche Canada

Sea To Sky.

Watch for changing conditions on solar aspects if the day is hot and sunny.

Summary

Confidence

High -

Weather Forecast

MONDAY: Mainly sunny, with increasing clouds late in the day. Light to moderate northerly winds. Treeline temperature near -2.TUESDAY: Cloudy with flurries. Moderate south-westerly winds. Treeline temperature near -1.WEDNESDAY: Clearing. Light winds. Treeline temperature near -5.More details can be found in the Mountain Weather Forecast.

Avalanche Summary

On Saturday, two skier-triggered wind slabs were reported: a size 1.5 wind slab from a cross-loaded feature on a northwest aspect at 1900 m, and a size 2 on a north aspect at 2350 m, both near Whistler.On Friday, evidence of a natural cycle which likely occurred near the end of the warming period earlier in the week was reported, with storm slab activity up to size 3 observed on north to east aspects in the Mt Currie area.On Thursday, avalanche control with explosives triggered numerous slab avalanches up to size 2. Cornice releases triggered wind slabs from the slopes below up to size 1.5. With colder temperatures expected this weekend, natural avalanche activity will likely taper off, but human triggering will be possible especially on leeward and cross-loaded slopes.

Snowpack Summary

Highly variable snow surfaces exist. On south-facing alpine slopes, you're likely to find scoured crusty surfaces, while reactive wind slabs have built on lee slopes facing roughly north. A melt-freeze crust has formed up to about 1900 m.On average, 180 cm of settled snow now sits on the mid-January crust which generally shows signs of bonding to the overlying snow; however, it has the potential to wake up with a large trigger such as a cornice fall. Below this, the snowpack is thought to be generally strong and well-settled.

Problems

Loose Wet

Slopes getting cooked by the sun may develop loose wet avalanche conditions.

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: North, North East, East, South East, South.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Wind slabs remain reactive to human triggers, especially on leeward slopes and cross-loaded terrain features.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Watch for signs of instability such as whumpfing, or cracking. Travel on ridgetops to avoid wind slabs on slopes below.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Cornices

Large looming cornices exist along ridgelines. They require respect and discipline. Give them an extra wide berth from above and below particularly during periods of warming or solar exposure.

Give cornices a wide berth when travelling on or below ridges.Falling cornices may trigger large avalanches on the slopes below.

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 12th, 2018 2:00PM