Avalanche Forecast
Issued: Feb 4th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Deep Persistent Slabs.
snow safety,
Parks Canada
A forecasted increased in wind from the SW will create new wind-slabs. The wind event could possibility trigger another cycle at higher elevation. Forecasters are uncertain if the wind will create slabs at tree-line.
Summary
Weather Forecast
A small system is expected to deliver up to 7cm over the next 72 hours. Strong wind from the SW will redistribute storm snow into lee areas. The temperature will rise slightly to about -5 in the valley and -8 at the ridge.
Snowpack Summary
30 to 70 cm of recent storm snow at higher elevations, with a rain crust up to 1800m. Wind slabs exist in the alpine and exposed areas at tree line. The Dec 31 layer of facets, surface hoar and sun crust is currently down 50-100cm. The deep persistent basal layer sits 20 to 40cm above the ground and is more developed in shallow snowpack areas.
Avalanche Summary
No avalanches reported or observed today. However, we are just coming off of a fairly substantial cycle from the last 5 days which saw large avalanches up to size 3.5 running to valley bottoms. Natural activity has tapered off, however human triggering remains likely in the alpine.
Confidence
Problems
Wind Slabs
Increasing wind into the strong range will load lee (NE) aspects, especially in the alpine starting late on Tuesday. Storm snow from last week will be easily distributed.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
This layer of surface hoar, facets and crusts is down 50 to 100cm and produces variable results, many in the hard range or no result.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Deep releases to ground are less likely, however, start zones will be loaded again with forecasted strong wind. Avoid exposure to start zones until there is less uncertainty.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
- Avoid shallow snowpack areas where triggering is more likely.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Feb 5th, 2020 4:00PM
