Avalanche Forecast
Issued: Mar 5th, 2020 4:00PM
The alpine rating is Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeWe're not expecting much overnight re-freeze Thursday night which may allow for increasingly sensitive cornices Friday. Watch for changing conditions late in the afternoon, a bit of precipitation and wind are expected before sunset.
Summary
Confidence
Low - Uncertainty is due to the timing of the incoming weather system.
Weather Forecast
Dramatic weather through the forecast period.
THURSDAY NIGHT: Freezing level around 2200 m, moderate to strong southwest wind, no precipitation expected.
FRIDAY: Overcast, freezing level around 1900 m, late in the day moderate to strong southwest wind will pick up and 5 to 15 mm of precipitation is possible, falling as rain at lower elevations and snow up high.
SATURDAY: Overcast, freezing level returning to valley bottom just before sunset and then staying near valley bottom all day, light variable winds at lower elevations, strong southwest wind in the alpine, 10 to 25 cm of snow possible.
SUNDAY: Overcast in the morning clearing off a little bit to broken cloud cover after lunch, freezing level near valley bottom, light to moderate southwest wind, no significant precipitation expected.
Avalanche Summary
A few small loose avalanches were observed on sun-exposed slopes on Tuesday and Wednesday. Over the weekend a few small wind slab avalanches (see this MIN report) and size 2 cornice falls were reported. The cornice falls did not trigger any slabs on the slopes below.
Snowpack Summary
Alpine terrain is heavily wind affected. A crust can be found near the surface up to 2000 m on solar aspects and up to 1700 m on all other aspects.Â
A thick rain crust that has facets associated with it sits 30-60 cm below the surface and can be found up to ridgetops. We have only seen one avalanche on this layer since February 17th. The mid-pack is well settled and strong, but the base of the snowpack contains basal facets that are most prominent in shallow rocky start zones.
Terrain and Travel
- Firm cornices can pull back into flat terrain at ridgetop if they fail.
- Stay in tune with the physical environment, conditions may change throughout the day.
Problems
Cornices
Cornices have grown large and loom over many ridge lines. They have potential to fail naturally during the heat of the day and could also fail if we get too close to them. Give them a wide berth.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 6th, 2020 5:00PM