Avalanche Forecast

Issued: Jan 30th, 2019 4:39PM

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

mconlan, Avalanche Canada

Northwest Coastal.

The positioning of the band of heaviest snowfall is uncertain. Some areas may see 20 cm on Thursday, some may get less than 10 cm. Where snow accumulates, treat it with added caution and make conservative choices.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

WEDNESDAY NIGHT: Cloudy with snowfall, accumulation 10 cm, freezing level 800 m.THURSDAY: Cloudy with snowfall, accumulation 15 cm, light to moderate southwest winds, alpine temperature -1 C, freezing level 800.FRIDAY: Cloudy with snowfall, accumulation 20 cm, light to moderate southwest winds, alpine temperature -5 C, freezing level 300 m.SATURDAY: Mostly cloudy with light snowfall, accumulation 5 cm, light southwest winds, alpine temperature -14 C, freezing level below valley bottom.

Avalanche Summary

On Wednesday, a few small pockets were reactive to skier traffic, with slabs up to 15 cm deep. Otherwise, no new avalanches were observed in the region.

Snowpack Summary

New snow will fall with an incoming storm. It will fall on a wind-affected surface, such as scoured snow on windward slopes and thicker snow deposits in lee terrain features. The snow will fall on a melt-freeze crust below treeline.Around 40 cm of snow may overly a weak layer of feathery surface hoar crystals in sheltered and shaded areas and a melt-freeze crust on southerly aspects. The layer is likely most prominent around Bear Pass and in the north of the region, but may still exist above around 1600 m in the south of the region.Within the middle and lower half of the snowpack, a few weak layers may still exist in the north of the region. These include another layer of surface hoar around 50 to 100 cm deep and a weak layer of sugary faceted snow around 200 cm deep.

Problems

Storm Slabs

New snowfall should accumulate quickly on Thursday, and it may be heavy. This snow may be reactive to human traffic. Conservative route selection is recommended.

Plan for a safe exit route from the backcountry.Make observations and assess conditions continually as you travel.If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Persistent Slabs

Two buried weak layers of surface hoar may be found around Bear Pass and to the north. These layers may also exist above 1600 m in the south of the region. They are around 50 cm deep and 70 to 100 cm deep, which are prime depths for human triggering.

Watch for signs of instability such as whumpfing, cracking, or recent avalanches.Good day to make conservative terrain choices.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Jan 31st, 2019 2:00PM