Avalanche Forecast
Issued: Apr 16th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Wind Slabs.
jonas hoke,
Parks Canada
The pockets of windslab in the alpine could be triggered by the weight of a skier, expect them to be most reactive where they sit on a crust.
Summary
Weather Forecast
On Wednesday a warm front will pass over us, followed by a costal low with precipitation and strong winds on Thursday-Friday.
Wednesday: Cloudy with sunny periods and isolated flurries. Treeline temperature: Low -5, High -3 C. Ridge Light (gusting strong) from the West. Freezing level: 2000 metres.
Snowpack Summary
Above treeline 10cm of settling snow sits on a variety of crusts. Above 2200m on Northerly slopes, a more winter like snowpack can be found, with pockets of windslab, a peristent weak layer down 20-50cm and a facetted mid and lower snowpack which is weak in shallow areas.
Avalanche Summary
There was isolated natural windslab activity observed during last weekends wind/snow event. The mid march PWL continues to produce whumphing in shallower snowpack areas and on moraine features, indicating unstable snow below.
Confidence
Problems
Persistent Slabs
Evidence from recent snowpack tests and whumphing would suggest that a weak layer of facets persists down 20-50cm in some areas. This layer will likely become reactive with loading from forecasted snow later in the week.
- Avoid shallow snowpack areas where triggering is more likely.
- Whumpfing is direct evidence of a buried instability.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Pockets of windslab can be found in alpine lees (more prevalent in the northern parts of the region). A significant snow event forecasted for late Thursday and Friday will build fresh reactive storm/wind slabs.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 17th, 2019 4:00PM
