Avalanche Forecast

Issued: Jan 2nd, 2017 4:47PM

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

shorton, Avalanche Canada

Cariboos.

Be extra cautious around south slopes: they're weak, wind-loaded, and getting hit by the sun.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

TUESDAY: A mix of sun and cloud, light to moderate northeast winds, alpine temperatures around -20.WEDNESDAY: Cloudy with sunny periods, light to moderate north winds, alpine temperatures around -16.THURSDAY: Cloudy with isolated flurries, light west winds, alpine temperatures around -14.

Avalanche Summary

On Sunday, several natural wind slabs were observed on all aspects and elevations during the peak of the winds. A skier also remote triggered a 70 cm deep wind slab on southwest-facing slope at treeline. Expect wind slabs to remain reactive to human triggers this week, especially on sun-exposed slopes. Also be aware that wind-loading and solar radiation may also make the persistent slab over the mid-December interface reactive in thin snowpack areas.

Snowpack Summary

Strong winds on Sunday had an extensive effect in exposed terrain at all elevations. Expect scouring, hard wind slabs, and thicker reactive wind slabs in unusual places as the winds shifted from west to northeast. Sunny weather is likely making the wind slabs extra touchy on south-facing slopes. The mid-December facet/surface hoar interface can be found buried 50-100 cm deep. The interface has been showing signs of gaining strength in thick snowpack areas, but remains a concern in thin snowpack areas throughout the region. The lower snowpack is well bonded and features a thick rain crust near the ground.

Problems

Wind Slabs

Southerly aspects are wind loaded and becoming unstable with solar warming. Watch for wind slabs in unusual places, including open areas at lower elevations.

Minimize exposure to sun exposed slopes when the solar radiation is strong.Avoid travelling in areas that have been reverse loaded by winds.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

A weak layer of facets from mid-December is buried 50-100 cm deep and has recently been reactive in parts of the region with thin snowpacks.

Avoid convexities or areas with a thin or variable snowpack.Choose regroup spots that are out of avalanche terrain.Minimize exposure to steep, planar south facing alpine slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 3rd, 2017 2:00PM