Avalanche Forecast
Issued: Jan 4th, 2019 4:50PM
The alpine rating is Deep Persistent Slabs and Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
FRIDAY NIGHT: Mostly cloudy, freezing level 1000 m.SATURDAY: Mostly clear, light southwest wind, alpine temperature -5 C, freezing level 1000 m.SUNDAY: Cloudy with light snowfall, accumulation 5 cm, light to moderate southwest winds, alpine temperature -5 C, freezing level 1300 m.MONDAY: Mostly cloudy, light to moderate west winds, alpine temperature -10 C, freezing level below valley bottom.
Avalanche Summary
A natural avalanche cycle may have occurred in the region with the substantial amount of recent snowfall. It may take a bit of time for us to obtain observations and determine the extent of what the storm did in the region.On Wednesday, a naturally-triggered large (size 3) avalanche was observed near Elkford, which likely released on Tuesday. See here. It ran full-path to valley bottom. In the far west of the region, the snowpack has been observed to be weak and touchy, as described here. New snow is loading this weak and touchy snowpack and increasing the likelihood of avalanche activity.
Snowpack Summary
Large variability in snow depths still exists in the region, ranging from practically no snow to almost 200 cm. Upwards of 60 cm of snow fell on Thursday and Friday above 1500 m. The snow fell with strong southwest winds. Expect the deepest deposits in the lee of terrain features. This snow will sit on previous hard wind slabs, a scoured and shallow snowpack on exposed ridges, and soft snow in sheltered areas. Below 1500 m, expect to find wet snow that will freeze into a hard crust once temperatures cool.All of this recent snow has loaded a weak snowpack. For average snowpack areas, expect to find weak and sugary faceted grains around 50 to 100 cm deep, which extend to the ground. This weak bottom half of the snowpack has been the culprit for large avalanches in the region over the past few weeks. It will take time for the snowpack to adjust to the added load.
Problems
Deep Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 5th, 2019 2:00PM