Avalanche Forecast
Issued: Mar 30th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Loose Wet and Cornices.
ahanna,
Avalanche Canada
Rising temperatures coupled with spring sun can pack a punch and quickly initiate natural avalanche activity and weaken cornices. Be ready to back off slopes as the surface becomes moist. Moderate wind could help keep things cool, but could also be building new wind slabs.
Summary
Confidence
Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.
Weather Forecast
Tuesday night: Scattered flurries. Moderate westerly wind. Freezing level 600 m. Alpine temperature -7.
Wednesday: Isolated flurries clearing in the afternoon. Moderate to strong southwest wind. Freezing level 1800 m. Alpine temperature -3.
Thursday: Flurries up to 5 cm. Strong southwest wind. Freezing level 1600 m. Alpine temperature -5.
Friday: Mix of sun and cloud. Light southwest wind. Freezing level 1400 m. Alpine temperature -7.
Avalanche Summary
We haven't received any reports of natural activity during the weekend's storm but a couple of involvements were reported on Monday. We really appreciate this MIN report of a size 1.5 skier triggered storm slab on a northeast aspect around treeline. Thankfully no one was injured. We regret to report a fatality on Eureka Peak, east of Williams Lake. A human-triggered cornice failure resulted in a size 2.5 slab avalanche. It is important to remember to stay well back from ridgetops that might be corniced and to avoid slopes with overhead cornice exposure especially under the current conditions where recent rapid growth has made them large and fragile. Strong sun will make cornice failures even more likely Wednesday afternoon.
Snowpack Summary
20-50 cm of recent snow has seen some redistribution by southwest to northwest wind, and seems to be bonding well with underlying surfaces. Dry snow that sees the sun or experiences above freezing temperatures for the first time Wednesday may become reactive as it settles rapidly. Crusty surfaces below treeline will become moist with rising freezing levels.
Recent warm weather patterns are expected to have helped old persistent weak layers heal including a few crusts buried over the last month and a facet layer 150 cm deep from the mid-February cold snap which has not produced avalanches since the first half of March.
Terrain and Travel
- Extra caution for areas experiencing rapidly warming temperatures for the first time.
- Remember that in the spring strong solar radiation and warm temperatures can weaken the snow in a matter of minutes.
- Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Problems
Storm Slabs
Storm slabs are most likely to be reactive:
- at elevations with dry snow experiencing rapid warming for the first time (around 1800 m)
- on dry southerly aspects seeing strong sun for the first time
- in freshly wind loaded terrain features at upper elevations
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Wet loose avalanches are possible below treeline.
Dry loose avalanches will be very likely on steep south facing slopes at upper elevations when the sun comes out in the afternoon.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are fragile due to rapid growth from recent snow and wind. Strong sun will further weaken them. Cornice falls are dangerous in their own right and they can also trigger slabs on slopes below.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 31st, 2021 4:00PM
