Avalanche Canada kdevine, Avalanche Canada

Northwest Coastal Avalanche Forecast

Dec 1st, 2019 4:00PM

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

The Northwest Coast is about to get slammed by a significant storm. Heavy snow and very high winds are expected on Monday. Expect Avalanche Danger to increase throughout the day.

Summary

Confidence

Moderate - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather.

Weather Forecast

SUNDAY NIGHT - Snow 10-15 cm / southwest winds, 40-70 km/h / alpine low temperature near -5

MONDAY - Snow, 15-25 cm / southwest winds, 60-100 km/h / alpine high temperature near -1 / freezing level 800 m

TUESDAY - Flurries, 5-10 cm / southwest winds, 30-50 km/h / alpine high temperature near -2

WEDNESDAY - Cloudy with sunny periods and isolated flurries / light north west winds / alpine high temperature near -6

Avalanche Summary

Avalanche activity is expected to be widespread on Monday. Avalanche hazard will increase throughout the day with heavy snow and strong winds in the forecast.

Snowpack Summary

10-15 cm of new snow from Sunday night is likely sitting on a mix of hard wind slabs, sugary faceted snow, and feathery surface hoar crystals. With heavy snow continuing throughout the day, there could be as much as 30-40 cm of new snow by the end of the day on Monday. Rain can be expected below about 800 m elevation. With up to 100 km/h winds in the forecast, the new snow will be redistributed into slabs that will likely be very reactive.  

Total snowpack amounts by the end of Monday may be in the 60-120 cm range, tapering quickly at lower elevations.

Problems

Storm Slabs

An icon showing Storm Slabs

Likelihood

Likely-Very Likely

Expected Size

1 - 2.5

A combo of heavy precipitation and up to 100 km/h winds suggest a serious storm slab problem will be developing on Monday.

Aspects:

All aspects.

Elevations:

All elevations.

Valid until: Dec 2nd, 2019 5:00PM