Avalanche Forecast

Issued: Jan 9th, 2016 7:30AM

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

pgoddard, Avalanche Canada

Purcells.

In isolated parts of the region, there is enough cohesive new snow to create a reactive storm slab on surface hoar. Investigate locally.

Summary

Confidence

Moderate

Weather Forecast

A dominant ridge of high pressure brings continued dry weather, a mix of sun and cloud, light northerly winds and cool temperatures. Above about 2000 m, a temperature inversion is expected to raise temps to around -4.For more details check out http://www.avalanche.ca/weather.

Avalanche Summary

A cycle of naturally-triggered size 1-2 loose dry avalanches was reported on Friday. Most were on steep alpine shady aspects.

Snowpack Summary

5-40 cm recent snow has buried large surface hoar on all aspects at and below treeline and on shaded aspects in the alpine. On south aspects, new snow may be sitting on a sun crust and/or surface hoar, providing an easy sliding layer. The recent snow is mostly unconsolidated and sluffs easily, except where it has been re-distributed by the wind. Fresh wind slabs may be sitting on 10-20 cm of facetted snow. In the mid and southern Purcells, two prominent layers of surface hoar are reactive in snowpack tests. These are buried down 25-50 cm and may have a cohesive slab above. Shallow snowpack areas and moraine features may have weak facetted snow near the ground that will require time and some warming to strengthen.

Problems

Loose Dry

Loose dry avalanches are especially likely on steep, shady slopes. They can gather enough mass to knock you around or bury you.

Avoid travelling in terrain that is exposed to sluffing from above.>On steep slopes, pull over periodically or cut into a new line to manage sluffing.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

In some parts of the region, wind slabs are lurking behind ridges and ribs. These may be especially touchy where they overlie surface hoar.

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

Persistent Slabs

We have not had any new reports of avalanches on this persistent weak layer of surface hoar that is buried down 40-60 cm. Professional operations continue to monitor this weak layer because the consequences of triggering are high.

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

Unlikely

Expected Size

2 - 4

Valid until: Jan 10th, 2016 2:00PM