Archived

Avalanche Forecast

Dec 15th, 2017–Dec 16th, 2017

Alpine

1: Low

The avalanche danger rating in the alpine will be low

Treeline

1: Low

The avalanche danger rating at treeline will be low

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: South Coast Inland.

A storm system is expected to arrive late Saturday and into Sunday, with highest snowfall amounts in the southern part of the region. Watch for new snow and wind building fresh slabs in lee areas.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

SATURDAY: Mostly cloudy, flurries. Accumulation up to 5 cm. Ridge winds moderate from the southwest. Temperature -4. Freezing level 700 m.SUNDAY: Snow. Accumulation 5-20 cm (highest amounts for Coquihalla area). Ridge winds moderate from the southwest. Temperature -2. Freezing level 700 m.MONDAY: Snow. Accumulation 5-15 cm (highest amounts for Coquihalla area). Ridge winds moderate from the west. Temperature -4. Freezing level 700 m.

Avalanche Summary

There have been no new avalanche reports since last weekend when numerous loose wet avalanches up to size 2 were observed on northerly aspects along the Duffey Lake Road with rapid daytime warming on Sunday.

Snowpack Summary

A light dusting of new snow now covers the crust that formed on all aspects with the exception of shaded north aspects at upper elevations where the old snow surface consisted of dry, sugary snow (facets). Beneath the snow surface the upper snowpack is well settled and overlies the late November rain crust, now 20-50 cm deep. Snowpack tests in the Duffey Lake area early in the week produced hard, resistant compression test results on small sugary, snow crystals (facets) associated with this layer. However these facets were noted to be showing signs of "rounding" or gaining strength. Treeline snow depths are approximately 1 m throughout the region.

Avalanche Problems

Wind Slabs

The new storm snow overlies a variety of old surfaces and may be easily triggered especially in areas where there has been additional loading from wind on top of a hard crust.

Be careful with wind loaded pockets in leeward areas, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2