Avalanche Forecast

Issued: Jan 23rd, 2020 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

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Be prepared to avoid avalanche terrain if there's heavy snowfall in your part of the region, snowfall amounts are highly variable.

Summary

Confidence

Low - Forecast snowfall amounts are uncertain. Recent weather patterns have resulted in a high degree of snowpack variability within the region.

Weather Forecast

THURSDAY NIGHT: Flurries continue overnight bringing another 10-20 cm of snow, strong wind from the southwest, freezing level drops to 1500 m with alpine temperatures around -2 C.

FRIDAY: Scattered flurries as the front leaves the region with most areas getting 5-15 cm of new snow and a few (uncertain) locations likely getting 15-25 cm, moderate to strong wind from the southwest, alpine temperatures around -3 C.

SATURDAY: Cloudy with some light flurries, light wind from the southwest, alpine high temperatures around -3 C.

SUNDAY: Mix of sun and cloud with light flurries starting in the afternoon, moderate wind from the south, alpine high temperatures around -3 C.

Avalanche Summary

There are no reports since the onset of the current storm, but it has likely caused natural storm slab avalanches in parts of the region that have received more than 20 cm of new snow. The additional load of new snow is also increasing the likelihood of deep persistent slab avalanches in northern parts of the region.

Snowpack Summary

A frontal system crossing the region is resulting in variable amounts of new snow and forecast amounts on Friday are also variable and uncertain. As of Thursday afternoon the northern part of the region received 15-30 cm and the southern part of the region received 10-15 cm. Another 15-40 cm of snow could accumulate by Friday afternoon, resulting in very thick and widespread storm slabs in some areas and more localized wind slabs in other areas. Wind over the past few days has been strong from the south, resulting in highly variable conditions in open terrain.

There are currently no concerns about deep weak layers in the south of the region (e.g. Coquihalla).

There have been two layers of concern in the northern half of the region (e.g. Duffey, Hurley). One is a weak layer of surface hoar buried about 100 cm deep that professionals are tracking at treeline in sheltered areas. The other is weak faceted grains and crusts near the bottom of the snowpack, that is most likely to be triggered in shallow rocky start zones.

Terrain and Travel

  • Travel in alpine terrain is not recommended.
  • Minimize exposure during periods of heavy loading from new snow, wind or rain.
  • Dial back your terrain choices if you are seeing more than 25cm of new snow.

Problems

Storm Slabs

An icon showing Storm Slabs

New snow, wind, and mild temperatures has likely formed touchy storm slabs in parts of the region, especially at higher elevations and wind affected terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Weak layers in the northern part of the region will be stressed by the storm, increasing the likelihood of large deep persistent slab avalanches. Two layers have been a concern in the north including a 100 cm deep surface hoar layer in sheltered areas around treeline and weak snow near the bottom of the snowpack in shallow rocky start zones at higher elevations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 24th, 2020 4:00PM