Avalanche Forecast
Issued: Jan 4th, 2020 4:02PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Deep Persistent Slabs and Loose Dry.
stephen holeczi,
Parks Canada
Lots of weather inputs which should prompt people to be very conservative with both the terrain they are traveling in and exposure to overhead terrain. The Considerable rating below treeline is for runout zones of large avalanche paths only.
Summary
Weather Forecast
Cooling temperatures to -15C in the alpine for Sunday. Winds will be in the moderate range with the odd strong gust at treeline and above, and around 5cm is in the forecast. The cooling trend continues Monday and another pulse of snow is expected on Tuesday.
Snowpack Summary
20-40 cm of storm snow, strong Westerly winds and mild temperatures are promoting storm slab formation. Some of the region has a midpack which sits over facets and depth hoar at the base, and other deeper areas have a well settled snowpack with limited facets and weak layers. Digging down to see what is in the snowpack in your area is important.
Avalanche Summary
Some increasing natural activity today with the strong winds. A size 3 on Mt. Field, a size 2.5 on Vermillion Peak, and another size 2.5 slide in the Sunshine area were directly observed today. We suspect there is a natural cycle occurring currently which will continue as long as the wind keeps up.
Confidence
Problems
Storm Slabs
The 20-40cm of storm snow has been accompanied by strong Westerly winds. Thick slabs in the lees of alpine and treeline features are likely forming due to the winds, and lower down the snow is settling into a slab.
- If triggered the storm slabs may step down to deeper layers resulting in large avalanches.
- Use caution in lee areas. Recent wind loading have created storm slabs.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Lots of uncertainty surrounding the distribution of this layer in Little Yoho and what will trigger it with all of the new inputs of snow, wind and warm temperatures.
- Avoid shallow snowpack areas where triggering is more likely.
- Be aware of the potential for wide propagations which could result in large avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Dry
While the wind stays elevated loose dry avalanches will be a problem in gully features.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 5th, 2020 4:00PM
