Avalanche Forecast

Issued: Jan 2nd, 2016 8:28AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs, Loose Dry and Wind Slabs.

Avalanche Canada bcorrigan, Avalanche Canada

The prime concern these days is surface hoar buried beneath a dense slab. Use caution moving into new areas, especially in the alpine.

Summary

Confidence

High - Due to the number and quality of field observations

Weather Forecast

The ridge of high pressure that has given us mild upper elevation conditions is forecast to move out of BC by tomorrow morning. Cooler air will move into the region bringing an end to the inversion and lowering temperatures in the alpine back to more normal below freezing values. The BC interior should remain dry until Tuesday next week. For more in-depth weather information, visit: http://www.avalanche.ca/weather

Avalanche Summary

Reports from yesterday indicate that loose-dry natural avalanches ( up to size 2.5 ) out of steep solar affected slopes remain a prime concern. There has also been reported a large, loose-dry avalanche from a North East facing slope in the alpine. Earlier in the week several large avalanches were triggered in the southern Purcells, west of Kimberly, on buried surface hoar. Something to keep in mind when looking for new terrain.

Snowpack Summary

Conditions are quite variable throughout the region. In the southern Purcells, (west of Kimberley), a prominent layer of large buried surface hoar has shown to be reactive to human triggers. In this part of the region, it's buried down 40 cm with a cohesive slab above it. Further north, this surface hoar layer is 60-120 cm down and has been sporadically reactive to skiers, most recently on North West facing alpine slopes near Golden. At alpine elevations, this interface exists as a surface hoar/facet layer sitting on a crust. The lower snowpack is generally considered to be well settled.  Solar aspects may now have sun crust from the recent warm temperatures.New and old wind slabs may be found in the lee of ridges and ribs on a variety of slopes, and surface hoar will be forming in protected cool areas.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Skiers have triggered four large persistent slab avalanches in the last couple of weeks. The culprit is surface hoar from early December down 40-60 cm. It exists at different elevations in various parts of the region, but it is definitely out there!
Dig down to find and test weak layers before committing to a big line. >Avoid exposed alpine faces, especially in the north of the region.>Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved, especially in the south of the region.>The new snow will require several days to settle and stabilize.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Loose Dry

An icon showing Loose Dry
This problem should cease to exist on solar aspects by Sunday morning. It will persist on North aspects for a while longer.
Be aware of party members below you that may be exposed to your sluffs. >Sluffs may trigger deeper instabilities.>

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs
Be cautious as you transition into wind affected terrain. >Use ridges or ribs to avoid pockets of wind loaded snow. >

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 3rd, 2016 2:00PM