Avalanche Forecast
Issued: Mar 13th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
ldreier,
Avalanche Canada
The ongoing storm will bring another 10 to 20 cm overnight and isolated flurries during the day. The snowpack will need time to stabilize. A good day to make conservative terrain choices and minimize overhead hazard!
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
SATURDAY NIGHT: Cloudy, 10 to 20 cm new snow, 60 km/h southwest wind, alpine low -12 C, freezing level lowering to valley bottom.
SUNDAY: Mostly cloudy, trace of new snow, 40 km/h westerly wind, alpine high -11 C.
MONDAY: Mix of sun and cloud, trace of new snow, 30 km/h southwest wind, alpine high -5 C.
TUESDAY: Mostly sunny, up to 5 cm new snow, 30 km/h southwest wind, alpine high 0 C, freezing level rising to 1000 m.
Avalanche Summary
Several small natural wet loose avalanches of size 1 and a few small skier triggered wind slab avalanches (size 1) were reported on Friday.
Snowpack Summary
The ongoing storm brought up to 50 cm snow combined with strong to extreme southwest wind and more snow is in the forecast for tonight. The new snow may overly widespread wind affect at alpine elevations, feathery surface hoar on northerly aspects and in sheltered terrain features around treeline, or a melt-freeze crust on southerly aspects and below treeline.
There are presently no widespread deeper concerns. However, faceted snow at the base of the snowpack exists in much of the region and always has the potential of being triggered in shallow, rocky slopes.
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
The storm brought up to 50 cm new snow since Thursday and another 10 to 20 cm is forecast for tonight. Storm slabs will be reactive to human traffic, especially where it sits on surface hoar on northerly aspects and in sheltered terrain features around treeline or a melt-freeze crust on southerly aspects and below treeline.
Moderate westerly wind will continue to form fresh reactive wind slabs. Strong to extreme southwest wind redistributed the new snow and developed touchy wind slabs in lee terrain features in the alpine and at treeline. The strong wind may have formed wind slabs lower down on lee slopes than expected. The wind contributed to cornice growth and the additional load may lead to cornice failures.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 14th, 2021 4:00PM
