Avalanche Forecast

Issued: Jan 1st, 2019 4:58PM

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

Avalanche Canada shorton, Avalanche Canada

An intense storm is hitting the Sea-to-Sky region on Wednesday afternoon and danger will increase throughout the day as storm snow accumulates.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

TUESDAY NIGHT: Light snow starting overnight with accumulations of 5-10 cm by the morning, moderate wind from the southwest, freezing level around 700 m with alpine temperatures dropping to -5 C.WEDNESDAY: 15-25 cm of snow, strong wind from the southwest, freezing level climbing to 900 m, alpine high temperatures around -2 C.THURSDAY: 20-50 cm of snow with freezing level climbing to 1600 m and strong to extreme wind from the southwest.FRIDAY: Another 20 cm of snow as freezing level drops to 1000 m and moderate wind from the west.

Avalanche Summary

Avalanche activity seems to have tapered off as temperatures have cooled off over the past few days. On Sunday there were reports of a few explosives controlled size 1-1.5 storm and wind slabs. On Saturday reports indicated several explosives controlled size 2 storm and wind slabs in the alpine and treeline. Some of these avalanches were running on a layer of surface hoar buried around December 26.Looking ahead, a widespread storm slab problem will develop with the incoming storm. The additional weight of the new snow could stress deeper weak layers too.

Snowpack Summary

Fresh storm slabs will start to form on Wednesday as a storm tracks across the region from the north. Wind loaded terrain will be the first to develop reactive slabs.30-50 cm of snow from the past week potentially sits on a weak layer of feathery surface hoar at treeline elevations and on a crust below 1800 m.A weak layer of sugary facets and surface hoar lies around 150 to 200 cm deep in the snowpack. There have not been reports of avalanches on this layer for over a week. That being said, this layer may still exist in isolated areas around treeline in some parts of the region.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy snowfall will build fresh storm slabs on Wednesday with the greatest danger on steep and wind loaded slopes.
Minimize exposure during periods of heavy loading from new snow and wind.Be careful with wind loaded pockets Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 2nd, 2019 2:00PM

Login