Avalanche Canada ldreier, Avalanche Canada

South Coast Avalanche Forecast

Jan 11th, 2020 4:00PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs.

Around 30 to 50 cm of snow are expected by the end of the day on Sunday. Snowfall amounts might vary dramatically throughout the region with higher amounts expected in the west. The avalanche danger will increase during the day with continuing snowfall. 

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

SATURDAY NIGHT: Cloudy with snowfall, accumulation 15 to 25 cm, light to moderate southwest wind, treeline temperature -5 C, freezing level at 500 m.

SUNDAY: Mostly cloudy with snowfall, accumulation of 20 to 25 cm, light westerly wind, treeline temperature -7, freezing level at 800 m.

MONDAY: Mostly cloudy with isolated flurries, light southwest wind, treeline temperature -12 C, freezing level below valley bottom.

TUESDAY: Mostly cloudy, light to moderate westerly wind, treeline temperature -15 C, freezing level below valley bottom.

Avalanche Summary

On Friday, the snow was reactive to skier traffic. Several small (size 1) skier triggered avalanches and a few natural avalanches were reported.

On Thursday, no new avalanches were reported. 

On Wednesday, a few natural wet loose avalanches up to size 1.5 were observed.

Storm slabs were reactive to human traffic on Monday. It is likely that a natural avalanche cycle occurred Monday night as the snow switched to rain.

Snowpack Summary

Another 30 to 50 cm of snow will fall by the end of the day on Sunday and add to the 40 cm of snow which fell over the past days. The snow will fall on a snow surface that was wind affected by moderate to strong southerly wind. Most precipitation of a previous storm on Tuesday fell as rain below about 1500 m. 

There is uncertainty how well the new snow will bond with the existing snow surface. Assess the bond of the recent snow before committing to avalanche terrain and travel conservatively.

Terrain and Travel

  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Avoid terrain traps where the consequence of any avalanche could be serious.
  • Travel in alpine terrain is not recommended.

Problems

Storm Slabs

An icon showing Storm Slabs

Likelihood

Very Likely

Expected Size

1 - 2.5

Another 30 to 50 cm of snow will fall by the end of the day on Sunday and add to the 40 cm of snow which fell over the past days. Snowfall amounts might vary throughout the region and higher amounts are expected in the west of the region. This storm will form storm slabs that will likely be reactive to human traffic. 

The recent snow is resting on a hard melt-freeze crust and it may not bond well to it. Assess the bond of the recent snow before committing to avalanche terrain and travel conservatively.

Aspects:

All aspects.

Elevations:

All elevations.

Valid until: Jan 12th, 2020 5:00PM