Avalanche Forecast

Archived

Dec 3rd, 2019–Dec 4th, 2019

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.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Northwest Inland.

Snow accumulation has varied across the region following the recent storm. In areas with higher snow totals, it may be possible to trigger storm slabs, especially near and above tree line where it has been drifted by wind.

Confidence

Low - Forecast snowfall amounts are uncertain. Uncertainty is due to the limited number of field observations.

Weather Forecast

Tuesday night: Mostly cloudy, scattered flurries with up to 5 cm of snow possible, west winds 30-60 km/h, alpine temperature -10 C

Wednesday: Cloudy with periods of sun, isolated flurries with up to 5 cm of snow possible, west winds 30-60 km/h, alpine high temperature -8 C

Thursday: Cloudy with periods of sun, isolated flurries with a trace of precipitation, light southerly winds, alpine high temperature -7 C

Friday: Mix of sun and cloud, isolated flurries with a trace of precipitation, light variable winds, alpine high temperature -10 C

Avalanche Summary

In areas that received higher snow accumulations and wind, storm slabs may be reactive to human triggers.

There have been no recent reports of avalanches in the region; however, there is very little information available this time. If you get out into the mountains, let us know what you see by submitting to the Mountain Information Network!

Snowpack Summary

In drifted areas, anywhere from 10-20 cm of new snow likely sits on a mix of melt-freeze crusts, hard wind slabs, sugary faceted snow, and feathery surface hoar crystals depending on location. This snow may form reactive storm slabs at and above treeline elevations, especially in wind affected areas.

Total snowpack depth ranges from 50-100 cm and tapers rapidly at lower elevations.

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.