Avalanche Forecast
Issued: Mar 12th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Cornices.
lbaker,
Avalanche Canada
New snow, warm temperatures and strong winds will create dangerous avalanche conditions on Monday.
Continually assess the bond of new snow to old surfaces and give weakening cornices a wide berth.
Summary
Confidence
Avalanche Summary
On Friday, the South Rockies Field Team was out in the Crowsness Pass. They observed strong ENE winds and building small but reactive pockets of wind slabs directly lee of ridges, trees, and high points. Check out the full report here.
On Saturday, small pockets of reverse loaded wind slabs were reported to be reactive to skier traffic at alpine and treeline.
Snowpack Summary
Accumulating flurries on Monday will cover a variety of surfaces including small pockets of wind slab on exposed south and west slopes, hard wind-affected surfaces in open areas, a sun crust on steep solar aspects, and facetted snow in sheltered areas.
A melt-freeze crust with facets above can be found 50 to 120 cm deep. It has not produced any recent avalanche activity in the region, however, rising freezing levels and additional snow may test this layer through the next few days.
The mid to lower snowpack is considered well-bonded at this point. Currently, we are not seeing the same basal weak layers and reactivity that many of the neighboring regions are experiencing this season.
Weather Summary
Sunday Night
Partly cloudy with isolated flurries, trace accumulation. Alpine temperatures reach a low of -6 °C. Ridge wind 40 km/h from the southwest. Freezing level at valley bottom.
Monday
Cloudy with mixed precipitation, 4-6 cm of new snow accumulation at upper elevations. Alpine temperatures reach a high of 0 °C. Ridge wind southwest 40 km/h gusting to 60 km/h. Freezing levels rise to 1900 meters.
Overnight, flurries intensify bringing 10-15 cm of snow to higher elevations.
Tuesday
A mix of sun and cloud with isolated flurries, trace accumulation. Alpine temperatures reach a high of -3 °C. Ridge wind southwest eases from 60 to 25 km/h. Freezing levels are around 1300 meters.
Wednesday
A mix of sun and cloud. Alpine temperatures reach a high of -2 °C. Ridge wind west 10-25 km/h. Freezing levels rise to 1500 meters.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Wind slabs may be poorly bonded to the underlying crust.
- Wind slabs are most reactive during their formation.
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
Problems
Wind Slabs
Strong southwest winds and new snow are forming fresh reactive wind slabs on north and east slopes. Previously small wind slabs were reactive on southwest slopes where they bonded poorly to the slick underlying crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Minimize your exposure to cornices, rising freezing levels will cause them to weaken and increase the possibility of failure. If they fail they can trigger large avalanches on the slopes below. Give them respect and a wide berth when you are traveling under them.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 13th, 2023 4:00PM
