Avalanche Forecast
Issued: Jan 8th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is
cgarritty,
Avalanche Canada
Give the new snow time to settle and bond before pushing into aggressive terrain. The possibility for a shallow slab release to trigger our weak basal snowpack can't be discounted. Thursday's forecast calls for sunshine, which will promote instability on sun-affected slopes.
Summary
Confidence
Weather Forecast
Wednesday night: Clear periods. Light to moderate west winds shifting to northwest.
Thursday: A mix of sun and cloud. Light northwest winds. Alpine temperatures around -14.
Friday: Mainly cloudy. Moderate southwest winds, becoming strong at ridgetop. Alpine high temperatures around -10.
Saturday: A mix of sun and cloud. Light southwest winds. Alpine high temperatures around -8.
Avalanche Summary
Reports from the Castle area on Tuesday showed explosives control yielding storm slab and wind slab releases to size 2 (large). Poor visibility was a factor limiting observations.
Further reports of avalanche activity in the neighbouring Lizard range on Tuesday showed numerous storm slabs releasing naturally as well as with remote triggers from skier traffic, and with explosives. Avalanches generally ranged from size 1 (small) to size 2.5 (large). The bulk of this activity was observed on north to east aspects.
Similar conditions were likely to exist in areas of the South Rockies that saw substantial snowfall over Monday night and Tuesday.
Looking forward, the recent snow should begin to form a more reliable bond with the old surface as our slab problems become increasingly limited to wind-loaded areas.
Snowpack Summary
The recent storm brought about 25-40 cm of new snow to the region over the early part of this week. This snow has been redistributed by moderate to strong south and southwest winds in exposed areas at higher elevations.
The new snow has buried older wind slabs and other wind-affected surfaces in open areas at all elevations. This older, wind-affected snow forms the upper part of a reasonably consolidated mid-snowpack which overlies our weak basal snowpack.
The bottom 30-50 cm of the snowpack consists of weak facets and crusts. Although these layers have been unreactive in recent snowpack tests and have not produced avalanche activity recently, there is the potential for them to become reactive with large loads or significant warming.
Terrain and Travel
- Avoid being on or under sun exposed slopes.
- Avoid freshly wind loaded terrain features.
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
Valid until: Jan 9th, 2020 5:00PM
