Avalanche Forecast
Issued: Nov 20th, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs.
Parks Canada/Parcs Canada,
Avalanche Canada
Continuing snowfall at 2-4 cm/day is building the Rockies snowpack. Several days of cold temperatures and light winds, from the east on Wed, have left 5-10 cm of soft snow on the surface. But, evidence of a proper weak layer at the base of the snowpack (crust/facets) also continues to emerge daily, with fresh avalanches on the ground.
Summary
Confidence
Moderate
Avalanche Summary
Lake Louise ski patrol reported another size 2 avalanche failing on the Oct crust (right above the ground) at 2470 m on a SE aspect (alpine terrain). This is the third day in a row with this kind of avalanche released with an explosive. Also, a few size 1's on the Nov 9 crust but no new windslabs.
Snowpack Summary
5-15 cm of soft surface snow sits over an early season snowpack ranging from 40-60 cm at treeline. Two weak layers exist: a Nov 9 crust/surface hoar about 25 cm above the ground, and an Oct crust/facet layer right above the ground. Avalanches have been failing on the Oct crust in alpine areas with explosives. We have minimal early season observations of how widespread this layer is, but we think the Oct crust is in most places at treeline and above.
Weather Summary
Currently a "bomb cyclone" is offshore of Vancouver Island, and an Arctic cold front is descending from the north and out on the prairie—this is our recipe for snow, which will be continuous but light through the weekend. Expect up to 5 cm a day and 10-15 by the weekend, with temperatures around -10 and generally light winds.
Terrain and Travel Advice
- Shooting cracks, whumpfs, and recent avalanches are strong indicators of an unstable snowpack.
- Avoid steep terrain, including convex rolls, or areas with a thin, rocky, or variable snowpack.
Problems
Deep Persistent Slabs
The Oct 23 crust, located just above the ground with weak facets above it, has been associated with explosive-triggered avalanches up to size 2 every day this week. So the problem exists, and we suspect it is fairly widespread across our region - but observations are limited.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 21st, 2024 4:00PM
