Avalanche Forecast

Issued: Apr 12th, 2019 3:59PM

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

ldreier, Avalanche Canada

Cariboos.

Snowfall amounts and timing of the approaching snowstorm are uncertain. If we receive much more than the expected 5 cm of snow then the strong southwest winds will likely create shallow wind slabs.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

FRIDAY NIGHT: Clear with cloudy periods / moderate west wind / alpine low -7 C / freezing level 800 mSATURDAY: Cloudy with a chance of sun / up to 5 cm of snow accumulation / strong southwest wind / alpine high -6 C / freezing level 1600 mSUNDAY: Cloudy / 10-15 cm snow accumulation / moderate west wind / alpine high -7 C / freezing level 1500 mMONDAY: Mix of sun and cloud / light southwest wind / alpine high -6 C / freezing level 1500 m

Avalanche Summary

On Thursday, a couple natural and machine triggered storm slab avalanches 20-40 cm deep and up to size 2.5 were observed on east facing alpine slopes.On Wednesday, no new avalanche activity was observed.On Tuesday, a small (size 1) slab avalanche 30 cm deep was remotely triggered by a skier from 80 m away on a northeast aspect at 2250 m. A layer of small surface hoar below the most recent snow may have been the weak layer. Additionally, several loose wet avalanches up to size 1.5 were triggered on solar aspects throughout the day by strong solar radiation.

Snowpack Summary

The new snow likely falls on a melt-freeze crust on all aspects except for north facing slopes above 2000 m, where the snow stayed dry. Last weeks unsettled weather produced 20-40 cm of snow which is slowly bonding on northern aspects where it might sit on surface hoar (weak, feathery crystals) in isolated locations. Older wind slabs sitting on surface hoar might still be sensitive to human triggers.Snowfall amounts taper quickly below treeline. Snow is disappearing rapidly at lower elevations.

Problems

Wind Slabs

Up to 40 cm of snow sits on a crust in most locations, except for high elevation, north facing terrain where the old snow surface has remained dry with isolated surface hoar. Wind slabs in these lee features may remain reactive to human triggers.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be careful as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 13th, 2019 2:00PM