Avalanche Forecast
Issued: Mar 12th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Wind Slabs.
kdevine,
Avalanche Canada
Rising freezing levels and sunshine will increase the likelihood of avalanches in many areas. Avoid exposure to cornices and steep sun-exposed slopes.
Summary
Confidence
Moderate - Uncertainty is due to difficult to forecast freezing levels. Recent weather patterns have resulted in a high degree of snowpack variability within the region.
Weather Forecast
FRIDAY NIGHT - Mainly cloudy with clear periods / light to moderate southwest wind / alpine low temperature near -2 / freezing level 1300 mÂ
SATURDAY - Mainly sunny / moderate southwest wind / alpine high temperature near 3 in the south, -1 in the north / freezing level 2500 m in the south, 2000 m in the north
SUNDAY - Mainly sunny with increasing cloud and a chance of flurries in the afternoon / alpine high temperature near 1 in the south, -2 in the north / freezing level 2300 m in the south, 1700 m in the north
MONDAY - A mix of sun and cloud / light variable wind / alpine high temperature near -3 / freezing level 1500 m
Avalanche Summary
Sunshine and rising freezing levels are expected to increase the likelihood of avalanches and cornice failures on Saturday. This trend is expected to be the most pronounced in the south of the region where freezing levels are expected to be higher than in the north.
On Thursday, there was a natural size 2.5 wind slab avalanche reported on a southwest aspect at 2200 m in the Duffey Lake area. There was also a natural size 2 cornice reported in the Coquihalla area.
Snowpack Summary
Wind slabs can be found on leeward slopes at upper elevations and may still be possible to trigger. Solar aspects likely have a crust on the surface, which may become moist/wet with exposure to sun and rising freezing levels. Soft, dry snow may be found in sheltered, shaded areas. Massive cornices exist on ridgelines, which can also act as triggers on slopes below.Â
In the north of the region, a weak layer of facets buried in mid-February may still be found on north aspects near treeline but has been gaining strength. The lower snowpack is generally well settled and strong.
In the south of the region, the mid and lower snowpack is generally well consolidated with no concerns of buried weak layers.Â
Terrain and Travel
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
- A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
- Minimize your exposure time below cornices.
Problems
Loose Wet
Warm temperatures and sunshine are expected to create prime conditions for wet loose avalanches. Solar aspects will be the most likely trigger areas, but warm temperatures could potentially cause wet loose avalanches on all aspects, especially at lower elevations.
This problem is expected to be most pronounced in the south of the region, however it is a concern in the north as well.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices weaken significantly when exposed to sun and warm temperatures. When they fail, they can have enough mass to be very destructive, and they can also trigger slab avalanches on the slopes below them.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Pay attention to the pattern of wind-drifting in the terrain where you are traveling and watch for cracking or changes in snow stiffness. Wind slabs are expected to be most prevalent in the north of the region.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 13th, 2021 4:00PM
