Avalanche Forecast
Issued: Jan 5th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
ahanna,
Avalanche Canada
Give the new snow time to settle and stabilize before pushing into bigger terrain.
Summary
Confidence
Weather Forecast
Sunday night: Clear periods with isolated flurries with up to 5 cm of new snow. Light west winds. Alpine low temperature around -10. Freezing level dropping to valley bottom.
Monday: Mix of sun and cloud with isolated flurries bringing up to 5 cm of new snow. Light northwest winds. Alpine high temperatures around -5.
Tuesday: Mix of sun and cloud with isolated flurries. Light variable winds. Alpine high temperatures around -8.
Wednesday: Mix of sun and cloud with isolated flurries. Light variable winds. Alpine high temperatures around -8.
Avalanche Summary
A widespread natural storm slab avalanche cycle occurred Friday and Saturday throughout the region where more than 40 cm of snow fell on Friday.
On Saturday, storm slabs up to size 2.5 and loose dry up to size 2 were observed in the Shames area and the Skeena corridor. And windslab avalanches up to size 2.5 were reported in Bear Pass. Avalanches up to size 3 were reported from the neighboring Howson range during the storm on Friday.
Snowpack Summary
80-100 cm of recent storm snow has been highly wind affected in the alpine. Expect to find deep wind loaded pockets below ridgetops and the lee sides of exposed features.
The new snow fell on a crust up to treeline and extensively wind affected surfaces at alpine and treeline elevations. The underlying snowpack is overall quite well consolidated, with an average depth of around 2 m. Two layers of surface hoar are now buried 80-150 cm deep. The recent widespread natural storm slab avalanche cycle was a good test on the reactivity of these layers, and there have been no reports of step-downs. Signs of instability that may be associated with these layers have been observed in isolates areas on low angle terrain below treeline, as detailed in this MIN report. The recent addition of significant snow loads will likely help heal and bond these weaknesses over time.
Terrain and Travel
- Avoid freshly wind loaded terrain features.
- The new snow may require another day to settle and stabilize.
- Brief periods of sun could quickly initiate natural avalanche activity.
Problems
Storm Slabs
80-100 cm of recent storm snow and strong winds have likely formed deep pockets of storm slab in lee features in the alpine and treeline. Watch for solar triggering of recent snow on solar aspects during periods of sun. Even after natural storm cycle avalanche activity starts to taper off, storm slab avalanches will remain sensitive to human triggering.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 6th, 2020 5:00PM
