Avalanche Forecast
Issued: Mar 17th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cgarritty,
Avalanche Canada
Light new snow and elevated winds should keep wind slab problems fresh and reactive to triggering in exposed areas. Monitor new snow accumulation and wind transport and be ready to step back if snowfall exceeds the forecast or you observe slab formation at lower elevations.
Summary
Confidence
Moderate - Forecast snowfall amounts are uncertain.
Weather Forecast
Wednesday night: Cloudy. Moderate to strong southwest winds.
Thursday: Cloudy with isolated flurries and a trace to 5 cm of new snow, continuing overnight. Moderate to strong southwest winds. Alpine high temperatures around -6.
Friday: Cloudy with continuing scattered flurries and a trace to 5 cm of new snow. Moderate to strong southwest winds. Alpine high temperatures around -9.
Saturday: Cloudy with isolated flurries and a trace of new snow, increasing a bit overnight. Alpine high temperatures around -9.
Avalanche Summary
No new natural avalanches were reported on Tuesday with limited field observations. A few size 1 skier triggered wind slab avalanches in the alpine were reported on Monday.
A natural avalanche cycle with storm slab avalanches up to size 2.5 (large) were reported in the southwest of the region throughout the weekend.Â
Snowpack Summary
About 5 cm per 12 hour period is expected to accumulate over the next couple of days, adding to 20-30 cm of new snow and snow from over the weekend. Storm totals in the southwest of the region are closer to 50-100 cm. Light forecast snow amounts and elevated winds are expected to continue forming fresh wind slabs on lee features below alpine ridgetops. At lower elevations, recent precipitation fell as rain.Â
Collectively, our new and recent snow overlies a variety of surfaces, including hard wind affected snow at alpine elevations, weak surface hoar crystals on northerly aspects and in sheltered terrain features around treeline, or a melt-freeze crust on southerly aspects and below treeline.
The mid and lower snowpack is reported as well settled and strong in most areas. However, weak facets exist at the base of the snowpack in the more shallow snowpack zones within much of the region and always have the potential of being triggered on steep, rocky slopes with a shallow or thin to thick snowpack; especially with large loads such as a cornice fall.
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
Problems
Wind Slabs
Southwesterly winds continue to form wind slabs that may be reactive to human triggers on lee and cross-loaded terrain in the alpine. Keep your guard up at lower elevations where recent accumulations may overlie a weak layer of surface hoar on sheltered north aspects or a crust on solar aspects.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 18th, 2021 4:00PM
