Archived

Avalanche Forecast

Nov 26th, 2017–Nov 27th, 2017

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Lizard-Flathead.

New snow and strong winds are expected to build storm slabs on the recent rain crust. Be extra cautious in leeward areas where wind-deposited, "pillowy" snow maybe present.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

As much as 10-15 cm of snow is forecast for Sunday night along with strong strong winds and lowering freezing levels.Monday: Mix of sun and cloud. Strong west wind. Alpine Temperature -5. Freezing level 1000 m.Tuesday: Flurries. Accumulation 5-10 cm. Moderate to strong southwest wind. Alpine Temperature -5. Freezing level 1100m.Wednesday: Mix of sun and cloud. Moderate to strong west wind. Alpine temperature -5. Freezing level 1100m.

Avalanche Summary

Large loose, wet avalanches were reported during last week's rain event. With the arrival of cooler temperatures on Saturday, reports indicate that the snow surface has refrozen and no new avalanche activity has been reported. As snow and wind load the old surface expect to see an increase in activity in the new storm snow.

Snowpack Summary

Approximately 5 cm of moist snow overlies the crust that formed following the rain event on November 23rd. The crust is up to 10 cm thick and extends to mountain top elevations on all aspects. The snowpack below the crust is moist to ground. Rain has washed away much of the snow below treeline and in many areas there is not enough snow to produce avalanches.

Avalanche Problems

Storm Slabs

Assess how the new snow is bonding to the old crust before committing to any open or steep slopes.

Use caution in lee areas in the alpine and treeline. Storm snow will form slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1 - 2