Avalanche Forecast

Issued: Jan 4th, 2017 4:35PM

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

The arctic outbreak continues with cold temperatures and no snow until Sunday at the earliest.THURSDAY: A mix of sun and cloud. Wind light southwest 15-25 Km/h. Temperatures between -16and -28 Celcius. No precipitation.FRIDAY: Sunny with cloudy periods. Wind becoming southwesterly 15-25 Km/h. Temperatures between -16 and -28 Celcius. No precipitation.SATURDAY: Increasing clouds late in the day with a chance of flurries. Winds light southerly 5-10 Km/h. Temperatures between -12 and -24 Celcius.

Avalanche Summary

No new observations.

Snowpack Summary

The snow from last week is showing signs of consolidating into soft slabs and sits on a variety of wind-affected surfaces at treeline and in the alpine. That said, the main concern is windslabs (and some cornices) forming in the alpine due 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.

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

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.

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 5th, 2017 2:00PM