Avalanche Forecast

Issued: Jan 7th, 2015 8:21AM

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

Avalanche Canada rbuhler, Avalanche Canada

Lingering storm instabilities means conditions may remain tricky for a couple days. Rapid warming or sun may increase the likelihood of triggering a slab.

Summary

Confidence

Fair

Weather Forecast

A strong warm ridge of high pressure that sits to the SW will interact with the Arctic air to the NE and create a temperature inversion. On Thursday, mostly cloudy conditions with periods of sun are expected across the region with light alpine winds. A layer of above-freezing air is expected to form between 2000 and 2500m. On Friday, the above-freezing air should persist but the valleys will remain cold. The inversion and warm air are expected to break down on Friday night and temperatures should return to normal on Saturday. Winds should remain light on Friday and Saturday. 3-6mm of precipitation are forecast for Saturday.

Avalanche Summary

On Tuesday, we received a report of numerous natural storm slab avalanches up to 1.5 at lower elevations. We have had no new reports from the alpine. A natural cycle was reported on Monday but observations were limited due to the storm. Natural avalanches activity is expected to decrease on Thursday but isolated natural avalanches are possible. The potential for human triggering remains high on Thursday.

Snowpack Summary

Recent winds have been highly variable with strong winds from almost all directions in the last few days. The most recent strong winds have been from SE-SW. Hard and soft wind slabs should be expected on a variety of slopes in open terrain. Rain was reported to almost 2000 m on New Years Day in the southern part of the region. Since then there's been around 30-70 cm of new snow. The new snow may be resting on older wind slabs or surface hoar in northern areas. In the mid-pack you may find another surface hoar layer, although it appears to be spotty in distribution. Near the bottom of the snowpack is a crust facet combo that was buried in mid-November. This layer is currently dormant and produces variable results in snowpack tests.

Problems

Storm Slabs

An icon showing Storm Slabs
Heavy snowfall and strong winds have built storm slabs in the south of the region. In the northern areas that received less snowfall, wind slabs are the primary concern.
Travel in avalanche terrain is not advised without professional level safety systems and guidance.>Avoid freshly wind loaded features.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
There are a couple buried persistent weak layers in the upper and mid snowpack. The weight of the new snow may increase the likelihood of triggering one of these layers.
Use caution around convexities, ridge crests, rock outcroppings and anywhere else with a thin or variable snowpack.>Be aware of the potential for large, deep avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 6

Valid until: Jan 8th, 2015 2:00PM

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