Archived

Avalanche Forecast

Dec 17th, 2017–Dec 18th, 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

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

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: South Coast.

Fresh storm slabs may bond poorly to chunky, variable crusts. Watch for how the new snow is bonding to the old surface.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Monday will see a brief lull in the active weather pattern before significant precipitation arrives on Tuesday.MONDAY: Cloudy with isolated flurries. Accumulation of 5 cm possible. Ridge wind light from the west. Temperature near 0. Freezing level 800 m.TUESDAY: Snow. Accumulation 20-30 cm. Ridge wind light from the southeast. Temperature near -1. Freezing level 700 m. WEDNESDAY: Sunny with cloudy periods. Ridge wind moderate northerly. Freezing level 600 m.

Avalanche Summary

On Sunday, skiers were able to trigger Size 1 storm slabs on westerly aspects near tree line in the North Shore mountains.

Snowpack Summary

10-25cm of snow from the weekend now sits on a widespread melt-freeze crust, which exists on all aspects and elevations. How well the incoming new snow bonds to this crust will be a critical determinant of avalanche danger on Monday.Below the snow surface, the upper snowpack is well-settled and bonding well to the late-November rain crust. Below tree line the snow pack is thin and there are many early season hazards. Snowpack depths range from 40 cm at 800 m elevation to 200 cm at 1220 m.

Avalanche Problems

Storm Slabs

Initial reports suggest the new snow is bonding well to an underlying crust. Take a conservative approach to terrain use if you find more than 20cm of new snow on a firm crust.

Watch for signs of instability such as whumpfing, cracking or recent natural avalanches.Choose conservative lines and watch for clues of instability.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 3