Avalanche Forecast

Issued: Jan 5th, 2017 4:56PM

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

mgrist, Avalanche Canada

Lizard-Flathead.

Be cautious near shallow rocky areas, where a small slab could trigger buried weak layers resulting in large avalanches.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

We're beginning to see a shift from the very cold conditions of late with daytime temperatures warming up by 5-10 degrees Celcius. Only some isolated flurries possible until late Sunday when a small amount of snow may fall (5-10 cms).FRIDAY: Mainly cloudy. Wind becoming southwesterly 15-25 Km/h. High temperatures near -14 and lows to -28 Celcius overnight. Small chance of isolated flurries. SATURDAY: Sunny breaks with increasing clouds late in the day. Slight chance of flurries. Winds light southerly. High temperatures near -12 and lows to -22 Celcius.SUNDAY: Increasing clouds. Wind light and variable. Temperatures between -15 and -24 Celcius; 5-10 cms light dry snow possible overnight.

Avalanche Summary

No new avalanche observations.

Snowpack Summary

We're seeing surface snow conditions ranging from very wind affected (sastrugi and hard slabs) to softer wind slabs. These sit on a variety of older wind-affected surfaces at treeline and in the alpine and have given easy test results in the top 15-20cms of the snowpack. That said, the main concern remains the windslabs (and some cornices) formed in the alpine thanks to the recent arctic outbreak winds. Deeper in the snowpack the mid-December persistent layer (facet interface) has been more prominent and reactive in the Corbin zone than closer to Fernie: Watch out for thinner snow packs and areas of crossloading in isolated areas (think shallow rocky areas) where an avalanche could step down to trigger deeper layers.

Problems

Wind Slabs

Variable northerly winds may redistribute the new snow into reactive wind slabs in exposed lee terrain. In shallow snowpack areas, these slabs could pull out to deeper layers below, increasing the size of an avalanche.

Avoid travelling in areas that have been reverse loaded by winds.Be cautious as you transition into wind affected terrain.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

Where denser snow overlies weak, sugary snow, there is the potential to trigger large, dangerous avalanches. Dig down and test for weak layers before committing to any steep slope.

Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.Danger spots are where denser snow overlies weak, sugary snow below.Be aware of the potential for full depth avalanches due to deeply buried weak layers.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 6th, 2017 2:00PM