Archived

Avalanche Forecast

Dec 8th, 2016–Dec 9th, 2016

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

1: Low

The avalanche danger rating below treeline will be low

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

4: High

The avalanche danger rating in the alpine will be high

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

Regions: South Coast.

Avalanche danger will increase throughout the day. The weather forecast remains uncertain, so consider the avalanche danger to be HIGH if there's more than 30 cm of new snow on Friday.

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

FRIDAY: 20-30 cm of new snow, 40-60 km/h southwest winds, treeline temperature at -5.SATURDAY: 20-30 cm of new snow, 20-40 km/h southwest winds, treeline temperature at -3.SUNDAY: 5 cm of new snow, light northwest winds, treeline temperature at -5.

Avalanche Summary

Avalanche activity has declined throughout the week, but the storm snow remained reactive on Wednesday as ski cutting produced a size 1 avalanche on a steep unsupported feature. The likelihood and size of storm slab avalanches will increase throughout the day on Friday with heavy snowfall and strong winds in the forecast.

Snowpack Summary

A heavy pulse of new snow is expected for Friday and Saturday, although the weather forecast models don't agree on how much. By Friday afternoon there may be 20-30 cm of new snow on top of 30-50 cm of settling snow from last Monday. Northeast winds have likely formed thin wind slabs in exposed alpine terrain. A sun crust has been reported on the surface of steep southerly aspects, which may bond poorly with the new snow. A rain crust exists below Monday's storm slab, and recent reports suggest the storm snow may still be poorly bonded to the crust on shady north aspects. Below the crust, the snowpack is settled and strong. Total snowpack depths are 160-200 cm at treeline.

Avalanche Problems

Storm Slabs

Storm slabs will build throughout the day with heavy snowfall and wind expected to start Thursday night. Very touchy storm slabs can be expected during periods of rapid loading.

Minimize exposure during periods of heavy loading from new snow and wind.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 2 - 2