Avalanche Forecast

Issued: Feb 1st, 2016 8:23AM

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

Avalanche Canada esharp, Avalanche Canada

Storm slabs are settling and gaining strength but the deeply buried persistent weak layer continues to be a concern for human triggering.

Summary

Confidence

Moderate - The weather pattern is stable on Tuesday

Weather Forecast

Tuesday: mainly cloudy with sunny breaks, no snow expected, light westerly winds, -5C at 1550m.  Wednesday: overcast with snow starting in the afternoon and up to 5cm expected overnight, light southerly winds, -5C at 1500m. Thursday: clearing, isolated flurries possible early in the day, light southwesterly winds, freezing level rising to 1500m.

Avalanche Summary

Although avalanche activity seems to be slowing we continue to receive reports of natural and skier triggered wind and storm slab avalanches up to about size 2 releasing down 20 to 30cm. No new reports of any avalanches releasing down to the deeper persistent weak layers.

Snowpack Summary

A soft storm slab 20-30 cm deep can be found across most of the region.  This may be sitting on a layer of surface hoar that was buried on January 27th.  Some areas have reported that previous strong winds destroyed this surface hoar, and may have stripped the old surface back to a hard rain crust before the recent storm snow arrived.  At lower elevations the storm slab may also be found on top of one or two thin freezing rain crusts up to about 2100 meters. Deeper in the snowpack, the persistent weak layer that was buried January 4th is now down 80-120 cm and continues to give sudden planar fractures in snowpack tests in some areas.

Problems

Storm Slabs

An icon showing Storm Slabs
The storm slab may continue to react to human triggers in isolated terrain where it is sitting on a buried surface hoar layer down 20-30 cm. The storm slab has not been reactive where it is bonding to a rain crust.
Be cautious as you transition into wind affected terrain. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
This persistent weak layer is probably now best described as a low probability but high consequence problem. Dig down (80-120 cm) to see if the surface hoar exists in your area.
Be aware of the potential for large avalanches due to the presence of buried surface hoar. >Dig down to find and test weak layers before committing to a big line. >

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 5

Valid until: Feb 2nd, 2016 2:00PM