Avalanche Forecast
Issued: Jan 16th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
cgarritty,
Avalanche Canada
Winds have had a big impact on our recent snow, scouring many exposed areas and redistributing snow into lower elevation features. Watch for newly formed wind slabs and maintain avoidance of steep, sheltered slopes where a stubborn storm slab may still react to a human trigger.
Summary
Confidence
Weather Forecast
Thursday night: Mainly cloudy with clear periods. Light southwest winds.
Friday: A mix of sun and cloud with flurries beginning overnight. Light southwest winds, increasing overnight. Alpine high temperatures around -9.
Saturday: Cloudy with continuing snowfall bringing 15-20 cm of new snow, increasing a bit overnight. Strong south winds. Alpine high temperatures reaching -3 as freezing levels rise to 1200 metres by afternoon.
Sunday: Cloudy with continuing snowfall bringing a final 15 cm of new snow and 2-day snow totals to about 60 cm. Precipitation possibly ending in light rain. Moderate to strong south winds easing over the day. Alpine temperatures reaching +1 as freezing levels rise to 1800 metres by afternoon and continue to rise overnight.
Avalanche Summary
MIN reports from Wednesday on the North Shore describe quite touchy conditions, with 5-15 cm-deep storm slabs triggering easily with skier traffic on steep slopes. Similar conditions are expected to have persisted through Thursday.
Looking forward, our most recent snow is expected to settle and form an increasingly strong bond with the surface, with surface instabilities becoming focused toward wind-loaded areas. Another storm arrives Friday night.
Snowpack Summary
25-30 cm of new snow from stormy weather on Wednesday and Thursday buried previously wind-affected surfaces in exposed areas at all elevations and soft, low density snow in sheltered areas.
The new snow brings snow totals from the past few days to about 120 cm. Collectively, all this snow rests on a hard melt hard melt-freeze crust below 1500 m and on previously wind-affected snow at higher elevations.
In some areas a weak layer of surface hoar exists above this crust. Recent snowpack tests on the North Shore have given variable, sometimes quite sudden results at this interface, particularly where this combination of crust and surface hoar was identified.
Terrain and Travel
- Avoid freshly wind loaded terrain features.
- Keep your guard up at lower elevations. Wind slab formation has been extensive.
- Seek out sheltered terrain where new snow hasn't been wind-affected.
Problems
Wind Slabs
Our most recent 20-30 cm of new snow has been forming an improving bond with the old surface, however areas where winds have created thicker, more reactive slabs remain a concern. About 120 cm of recent snow now exists above a hard crust that is present below 1500 m in elevation. There may be isolated areas where surface hoar sitting on this crust permits very deep storm slab releases.
Aspects: North, North East, East, West, North West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 17th, 2020 5:00PM
