Avalanche Forecast

Archived

Dec 13th, 2019–Dec 14th, 2019

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

South Coast.

Fresh storm slabs may be reactive to human triggering, especially in wind loaded areas, and at upper elevations.

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

FRIDAY NIGHT - Cloudy with clear periods and isolated flurries / light west winds / alpine low temperature near -2 / freezing level 600 m

SATURDAY - Mainly cloudy / light west winds / alpine high temperature near -3 / freezing level 500 m

SUNDAY - A mix of sun and cloud / light northwest winds / alpine high temperature near -4

MONDAY - Cloudy with sunny periods / southwest winds, 20-30 km/h / alpine high temperature near -2

Avalanche Summary

There have been no recent reports of avalanches, but there is very little information available at this time. Based on recent weather events, it is likely that a natural avalanche cycle occurred at upper elevations on Thursday, and may have continued into Friday.

With a more stable weather pattern over the weekend, it is likely that natural avalanche activity has tapered off. However, storm slab avalanches could still be triggered by humans, especially in wind loaded areas at higher elevations.

If you get out into the mountains, let us know what you see by posting to the Mountain Information Network!

Snowpack Summary

30-50 cm of recent fresh snow at treeline and in the alpine sits on a weak layer of surface hoar above about 1400 m. Strong southwest winds have likely redistributed the new snow and formed reactive storm slabs. The new snow sits on a very thin snowpack of about 30 cm at 1500 m.

Problems

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.