Avalanche Forecast
Issued: Mar 15th, 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
Up to 15 cm new snow and moderate to strong southwest wind will form reactive wind slabs. In the southwest of the region the snowpack might need time to stabilize after the big weekend storm. Watch for signs of instability like whumpfing, hollow sounds and shooting cracks.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
MONDAY NIGHT: Cloudy, 5 to 10 cm new snow, 50 km/h southwest wind, alpine low -7 C.
TUESDAY: Cloudy, up to 5 cm new snow, 40 km/h southwest wind, alpine high -1 C, freezing level rising to 1100 m.
WEDNESDAY: Mostly cloudy, 5 to 10 cm new snow, 40 km/h southerly wind, alpine high 0 C, freezing level 1100 m.
THURSDAY: Mostly cloudy, trace of new snow, 20 km/h southeast wind, alpine high 0 C, freezing level 1000 m.Â
Avalanche Summary
A natural avalanche cycle with storm slab avalanches up to size 2.5 and small wet loose avalanches started on Saturday and lasted into Sunday in the southwest of the region. On Sunday, explosives control work resulted in a few small storm slabs and cornice failures of size 1.5. On Saturday, explosives triggered wet slab avalanches up to size 2.5. A few small natural wind slabs on steep northeast facing alpine features and several small wet loose avalanches at all elevations were observed as well.Â
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
Most of the region received around 20 cm new snow during the recent storm except for the southwest of the region where snow amounts range between 50 and 100 cm. The snow fell with strong southerly wind. At lower elevations the precipitation fell as rain. 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
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
Up to 15 cm new snow are forecast by the end of the day. In the southwest of the region where the recent storm brought 50 to 100 cm, storm slabs might remain reactive to human traffic, especially where the snow 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 to strong southwest wind will redistribute loose snow where available and develop touchy wind slabs in lee terrain features in the alpine and at treeline. Recent strong wind may have formed wind slabs lower down slopes than expected.
The wind will contribute to cornice growth and the additional load may lead to cornice failures.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 16th, 2021 4:00PM
