Avalanche Forecast
Issued: Feb 19th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Garth Lemke,
Monitor the change in weather increasing the danger on Sunday and Monday with potentially 20cm of snow, extreme winds, rising temperatures and high relative humidity. Weather models are not agreeing.
Summary
Weather Forecast
Saturday is expected to be sun and flurries, a trace of new snow, -11C, and Light gusting 60km/hr Westerly winds. Sunday will be a change in weather with periods of snow, 17cm during the day, -6 C, and 35 to 80 km/hr winds. On Monday, another 4cm of snow and gusting 80km/hr winds.
Snowpack Summary
Alpine winds have created wind slabs or hard surface conditions in high alpine lee features particularly where local terrain increases the wind action. The upper snowpack are facets and mixed forms over a supportive mid-pack. Thinner snowpack areas it is weak, un-supportive, and facetted.
Avalanche Summary
There was no field patrol on Friday. Thursday's patrol into Whistler creek did not note any new activity. Wednesday's patrol was cut short due to a rescue.
Confidence
Intensity of incoming weather systems is uncertain on Sunday
Problems
Wind Slabs
Wind-slabs exist in the alpine and some locations have reported the 'hollow' noise while walking which can be a sign of potential instability. Continuing wind adds to this condition.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Travel on ridgetops to avoid wind slabs on slopes below.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Deep Persistent Slabs
Caution in thin snowpack areas where triggering is more likely. This is a low probability but high consequence problem.
- Avoid shallow snowpack areas where triggering is more likely.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 20th, 2021 4:00PM
