Avalanche Forecast
Issued: Feb 18th, 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,
The Tonquin Area is officially open for winter travel. Use caution as this area is typically more shallow and therefore a weaker snowpack. Otherwise, be vigilant in all terrain for shallow locations being potential human trigger spots.
Summary
Weather Forecast
Friday is expected to be sun and flurries, a trace of new snow, -9C, and Light gusting moderate SW winds. Saturday will be unsettled weather, only a trace of snow, -11 C, and light gusting strong SW winds. There may be a shift in the weather on Sunday with 18cm of snow and strong winds by the end of the day.
Snowpack Summary
Alpine winds continue to create wind slabs 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
Thursday's patrol into Whistler creek did not note any new activity. Wednesday's patrol was cut short due to a rescue.
Confidence
Forecast snowfall amounts are uncertain on Sunday
Problems
Wind Slabs
Moderate to strong SW winds in the alpine and higher RH values are likely creating wind slabs.
- Travel on ridgetops to avoid wind slabs on slopes below.
- 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.
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 19th, 2021 4:00PM
