Avalanche Forecast
Issued: Mar 14th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Wet.
swerner,
Avalanche Canada
Reactive storm slabs should be expected on Wednesday. Seek out low-angle sheltered terrain for the best riding.The March sun packs a punch and can quickly destabilize the snowpack on solar slopes.
Summary
Confidence
Avalanche Summary
On Tuesday, a skier-triggered storm slab was reported on Zoa. The slab was a size 1.5 and was triggered near the top of the slope with no involvement. It was 40 cm deep and slid clean on the underlying old snow surface. Check out the MIN HERE. Thanks for the report and happy to hear everyone was ok.
A natural persistent slab size 3 was reported on Tuesday but it's suspect that it failed Monday during the storm. This avalanche happened on a shady aspect at 1800 m, with the failure plane unknown but suspect an early March interface.
On Monday, no recent avalanches were reported. Natural wind slab activity has been reported this past weekend. They failed on the north and northeast aspects and were released at a depth of 10 to 40 cm.
Natural and human-triggered avalanche activity may occur throughout the week with rising freezing levels and solar radiation.
Snowpack Summary
Up to 40 cm of recent storm snow overlies a sun crust on solar aspects and a melt-freeze crust at lower elevations. Reports indicate that the slab may poor bond to the underlying crust, especially around 1500 m. In sheltered areas, the new snow may sit above a spotty surface hoar layer. Recent strong southwest winds may have formed fresh wind slabs at higher elevations and cornices loom over ridgelines.
There are several crusts in the mid/lower snowpack. Their depth ranges from 150 to 250 cm.
A large trigger, such as a cornice fall or a smaller avalanche in motion, could trigger a very large avalanche on one of these deeply buried weak layers. A single rider is unlikely to trigger this layer unless they are in a steep, rocky, and shallow snowpack area.
Weather Summary
Tuesday Night
Cloudy, 5 cm accumulation, winds southwest 15 to 55 km/h, with freezing levels falling to 400 m.
Wednesday
Cloudy with sunny breaks late in the day. Isolated flurries. Winds southwest 20 to 55 km/h, freezing levels 700 m.
Thursday
A mix of sun and cloud. Winds southeast 20 km/h gusting to 50 km/hr. Alpine high of +1 and freezing levels 1500 m.
Friday
A mix of sun and cloud. Winds 10-20 km/hr from the southeast. Alpine high +4 with freezing levels 1700 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Use increased caution at all elevations. Storm snow is forming touchy slabs.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
Up to 40 cm of recent storm snow builds reactive storm slabs. These seem to be easily human-triggered as the slabs have a poor bond to the underlying crust.
Moderate to strong southwest winds may have formed new wind slabs on lee slopes at treeline and above.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Strong solar radiation may weaken the surface snow creating wet loose avalanches from steep solar slopes.
Aspects: South East, South, South West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 15th, 2023 4:00PM
