Avalanche Forecast

A warm wet storm continues to impact the region Sunday before giving way to cooler temperatures Monday.

SATURDAY NIGHT: Freezing level around 1300 m, 1 to 5 cm of snow possible, strong west/southwest wind.

SUNDAY: Overcast, freezing level around 1100 m, strong west/southwest wind, 5 to 10 cm of snow possible.

MONDAY: Scattered cloud cover, freezing level at valley bottom, moderate southwest wind, 2 to 5 cm of snow possible.

TUESDAY: Scattered cloud cover, freezing level beginning at valley bottom rising to about 1500 m by sundown, strong to extreme southwest wind, trace of snow possible.

On Friday natural storm slabs to size 2 were reported. Recent observations have been scant, but there were a few large human-triggered persistent slab avalanches in the neighbouring Cariboo region last weekend (on northeast slopes near treeline).

The persistent slab avalanche problem is now a low-probability/high-consequence situation. There were many notable avalanches between Dec 18-20 including natural, accidental, and remotely triggered avalanches up to size 2.5 at Pine Pass, Torpy, and Tumbler Ridge. This weekend's storm is likely to produce similar activity and should be a great test for our snowpack in the long term.

The region has picked up 10 to 55 cm from the Friday/Saturday storm with the deeper amounts being found to the north. 40 to 120 cm of snow is now sitting above a mix of interfaces that were buried in early December. In some (but not all) terrain these interfaces may be composed of weak surface hoar or weak crusts and facet layers, creating a persistent slab avalanche problem. 

We do not see a clear pattern in which parts of the region or which types of terrain this problem is still a concern. 

Between Dec 18-20 there was compelling evidence of this problem around Pine Pass, the McGregors, and Tumbler Ridge. This problem has not been found at Renshaw, but has been found in the surrounding areas near McBride. There is no recent information from Kakwa. Overall, uncertainty about these layers make it difficult to have confidence in challenging or complex avalanche terrain without very careful terrain evaluation and an in-depth understanding of local snowpack conditions.

Snow depths are in 150-250 cm around Pine Pass, the McGregors, and McBride and closer to 100-150 cm around Tumbler Ridge. In shallower areas along the eastern slopes there could be weak snow at the bottom of the snowpack that could be a concern in steep rocky alpine terrain.

• Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
• In times of uncertainty conservative terrain choices are our best defense.
• Be aware of the potential for large avalanches due to the presence of buried persistent weak layers.