Avalanche Forecast

Issued: Jan 3rd, 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.

bcorrigan, Avalanche Canada

Purcells.

Use great caution when venturing into new terrain, the persistent, weak surface hoar layer may still be reactive to riders.

Summary

Confidence

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

Weather Forecast

A high pressure ridge will dominate the weather pattern in the interior of BC for the forecast period. The upper level inversion we enjoyed this past week has moved out of the region bringing more seasonal January temperatures. Valley cloud is likely in the morning with cold alpine conditions. Precipitation with light to moderate south winds are in the forecast for Monday and Tuesday, although the timing and amounts are still uncertain. For more in-depth weather information, visit: http://www.avalanche.ca/weather

Avalanche Summary

Loose-dry natural avalanches ( up to size 1.5 ) out of steep solar affected slopes are still being reported. Earlier in the week several large avalanches were skier triggered in the southern Purcells, west of Kimberly, on buried surface hoar. Something to keep in mind when looking for new lines!

Snowpack Summary

Conditions are quite variable throughout the region. In the southern Purcells, (west of Kimberley), a prominent layer of 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 is forming in protected cool areas.

Problems

Persistent Slabs

This persistent slab problem is not going to go away soon. It's a good time to dig a pit and test the reactivity of the slab before venturing into big terrain.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved, especially in the south of the region.>Avoid exposed alpine faces, especially in the north of the region.>Dig down to find and test weak layers before committing to a big line. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Loose Dry

The loose-dry problem should now be confined to steep northerly aspects, although some big south slopes may still unload given the right amount of warming. A large dry sluff could definitely do some damage!

Sluffs may trigger deeper instabilities.>Be aware of party members below you that may be exposed to your sluffs. >

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

The recent warm temperatures will have helped bond many of the wind slabs. They may still be reactive on high northeast, north, and northwest aspects.

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

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 4th, 2016 2:00PM