Avalanche Canada cgarritty, Avalanche Canada

South Coast Inland Avalanche Forecast

Jan 15th, 2020 4:00PM

Forecast snowfall is uncertain, but strong winds are expected to be widespread. HIGH danger will apply to areas that see 20-25 cm of new snow or more accumulate by Thursday morning. CONSIDERABLE danger will exist in areas that see less than 20 cm of new snow. 

Summary

Confidence

Low - Forecast snowfall amounts are uncertain.

Weather Forecast

Wednesday night: Cloudy with light flurries bringing up to 5 cm of new snow to the south of the region and snowfall bringing 25-35 cm of low density new snow to the north of the region. Strong to extreme south winds.

Thursday: Cloudy with easing flurries bringing 5-20 cm of new snow, again focused in the north. Strong southwest winds easing over the day. Alpine temperatures around -12.

Friday: Broken cloud cover. Light south winds. Alpine high temperatures around -13, closer to -10 in the south of the region. 

Saturday: Cloudy with flurries bringing 3-5 cm of new snow. Light to moderate south winds. Alpine high temperatures around -7, closer to -4 in the south of the region.

Avalanche Summary

Reports from the region have been limited during the cold snap, however a MIN from Tuesday describes winds actively forming new slabs in the Duffey area.

On Monday small wind and storm slabs to size 1.5 were observed in the recent storm snow. Interesting to note that wind slabs were observed in open treeline features which speaks to the widespread nature of Sunday's north wind event.

On Saturday, the snowpack was reactive to explosive triggers. Some avalanches stepped down to a feathery surface hoar layer buried 50-60 cm deep.

Last Thursday, explosive control work produced a size 2 avalanche off the Duffey Lake road that released on the mid November facet/crust layer.

Snowpack Summary

On Sunday, funky wind out of the north and northeast associated with an arctic front likely formed fresh wind slabs in locations we aren't used to seeing them. 

Previous to Sunday's wind event, the riding quality has been phenomenal throughout the region, but there are still some areas with concerns deeper in the snowpack:

  • A deep persistent weak layer remains a serious concern at the bottom of the snowpack in the northern half of the region (e.g., Duffey, Hurley). It's made up of sugary faceted grains and a hard melt-freeze crust. This is an atypical setup for this part of the province, it's not going away anytime soon, and we should all probably remain a bit wary of big alpine lines, at least for now.
  • There are currently no concerns about deep weaknesses in the snowpack near Coquihalla summit and elsewhere in the south of the region.
  • Most of the region has an unusually thin snowpack in the alpine.

Terrain and Travel

  • Make observations and assess conditions continually as you travel.
  • Storm slab size and sensitivity to triggering will likely increase through the day.

Valid until: Jan 16th, 2020 5:00PM