Avalanche Forecast

Issued: Jan 22nd, 2018 4:38PM

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

Avalanche Canada jlammers, Avalanche Canada

Avalanche conditions are forecast to intensify throughout the day on Tuesday. Pay close attention to how much snow falls in your riding area, and be prepared to back-off to simple terrain.

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain on Tuesday

Weather Forecast

Tuesday: 12-18cm of new snow / Strong southwest winds / Freezing level at 1000mWednesday: 15-20cm of new snow / Moderate southerly winds / Freezing level at 1200mThursday: 3-5cm of new snow / Moderate southerly winds / Freezing level at 800m

Avalanche Summary

There have been no new reports of avalanche activity, but that may speak more to a lack of observations rather than actual conditions. On Sunday, an impressive natural storm slab avalanche cycle is expected to have occurred particularly in the northwest side of the region where snowfall and wind were most intense. Looking forward, forecast snow and wind will promote ongoing storm slab avalanche activity, especially in higher elevation, lee terrain.

Snowpack Summary

By Monday morning the 48 hour snowfall totals were around 60cm in the Duffey/ Tenquille areas. Thanks to strong to extreme southwest winds, I would anticipate redistribution of the recent storm snow at all elevation bands with storm slabs lurking in lee and cross-loaded features. Further south in Coquihalla area, 48 hour storm totals were closer to 35 cm and winds were much lighter.50-120cm below the surface you'll likely find a few crusts that were buried during the first few weeks of January. Due to limited observations, not much is known about the current reactivity of these layers.The lower snowpack includes the mid-December crust layer. I'd expect an improving bond at this interface; however, the load of the new snow may tip the balance and reactivate this layer in isolated terrain - particularly in the north of the region where it's shown prolonged reactivity in snowpack tests.

Problems

Storm Slabs

An icon showing Storm Slabs
New snow and wind on Tuesday will add to an ongoing storm slab problem with increased reactivity expected in high elevation lee terrain. Conditions are forecast to intensify throughout the day.
Be cautious as you transition into wind affected terrain.The new snow may require several days to settle and stabilize.Stay off recent wind loaded areas until the slope has had a chance to stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1.5 - 2.5

Valid until: Jan 23rd, 2018 2:00PM