Avalanche Forecast

Issued: Dec 16th, 2019 5:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

Time to turn on our avalanche brains again for the season in the South Coast ranges. Start by equating the depth of new snow with the depth of a possible storm slab release. Expect the greatest depths at higher elevations and in wind loaded areas.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

MONDAY NIGHT: Cloudy with continuing flurries transitioning to rain or wet flurries. 5-10 cm of new snow. New snow totals of 10-20 cm.

TUESDAY - Wet flurries bringing another 10-15 cm of new snow. Strong southwest winds. Alpine high temperature near 0 with freezing level to 1400 metres.

WEDNESDAY - Rain and snow bringing up to 10 cm of new snow by end of day. Moderate to strong south winds. Alpine high temperature near 0 with freezing level to 1400 m, dropping to 800 m in the evening while flurries increase.

THURSDAY: Continuing flurries bringing about 10 cm of new snow, increasing and transitioning to wet flurries or rain overnight. Moderate south winds. Alpine high temperatures around -1 with freezing level to 1200 metres, increasing to 1500 metres overnight.

Avalanche Summary

There have been no recent reports of avalanches, but there is very little information available at this time.

Looking forward, forecast snowfall will steadily increase chances of storm slab avalanches as it increases in depth and is redistributed by wind.

If you get out into the mountains, let us know what you see by posting to the Mountain Information Network!

Snowpack Summary

A layer of new snow is beginning to accumulate over the region. This time around, it is burying an array of smooth surfaces provided by the 30-50 cm of snow we received last week at treeline and in the alpine. Recent observations show the new snow will bury a weak layer of surface hoar in the North Shore mountains.

The older storm snow sits on another layer of surface hoar above about 1400 m. Below this elevation, the older snow mainly covers ground, smoothing over previous ground roughness and giving us planar surfaces for future avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Forecast new snow is expected to form unstable storm slabs over the near term. A weak layer of surface hoar recently observed on the North Shore mountains may make slabs especially touchy. Expect slabs to increase in size and reactivity over the day.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Dec 17th, 2019 3:30PM