Avalanche Forecast
Issued: Mar 27th, 2022 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Persistent Slabs.
dboucher,
Avalanche Canada
With no or minimal overnight freezing, warm temperatures, sunshine and light rain will continue to destabilize the snowpack on all aspects and all elevations. Thoughtful terrain choices and conservative decision-making are essential for safe travel in the backcountry.
Summary
Confidence
Moderate - We have a good understanding of the snowpack structure and confidence in the weather forecast Uncertainty is due to the fact that cornice falls are particularly difficult to forecast. Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.
Weather Forecast
An upper ridge builds in from the west and moves across the province on Monday. This will be associated with drying and clearing conditions before the next storm system moving in for Wednesday.Â
SUNDAY NIGHT: Mainly cloudy. No precipitation. 10-15 km/h southerly winds. Low alpine temperature +5 C with freezing level around 2400 m.
MONDAY: Cloudy with sunny periods and scattered flurries/showers. 5 mm. 15-25 km/h southwesterly winds becoming northwesterly in the afternoon. High alpine temperature +4 C with freezing level around 2200 m.
TUESDAY: Sunny with cloudy periods. No precipitation. 15-25 km/h northeasterly winds. High alpine temperature +2 C with freezing level around 2000 m.
WEDNESDAY: Mainly cloudy with scattered flurries. 5-10 cm. 25-40 km/h southwesterly winds. High alpine temperature -2 C with freezing level around 1700 m.
Avalanche Summary
On Saturday, several small size 1 loose wet avalanches were triggered by skiers on steep solar aspects slopes.
Snowpack Summary
The upper snowpack is going through a diurnal melt freeze cycle with minimal overnight refreezing. Refrozen crust on all aspects as high as 2500 m, softening in the afternoon at all elevations and especially on steep, sunny slopes. Recent warm temperatures, sun, and rain have made the top 20-40 cm of the snowpack moist. At very low elevations, the snowpack may be wet and isothermal, depending on overnight freezing levels.Â
40 to 70 cm below the snow surface, you'll find a frozen sun crust on solar aspects, and weak, feathery surface hoar crystals on shaded aspects. This layer was buried in early March. During the last storm, and on the warmest days earlier this week, it produced surprising avalanches in the Selkirks (east side of the region). The recent warm weather may help this layer bond in the long run, but it's not yet time to take it out of your danger assessment for the day.
The mid and lower snowpack are generally strong and well bonded.
Terrain and Travel
- Avoid steep slopes when air temperatures are warm, it is raining, or solar radiation is strong.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Loose Wet
Wtih no overnight freezing forecasted, the surface snow will not refreeze except maybe at very high elevations. The more the snow feels like a slurpy, the more likely loose wet avalanches will become. Especially avoid steep slopes when they are baking in the sun.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are large at this time of the year and warm temperatures may cause them to become weak. Cornice failures are dangerous on their own, but also have the potential to trigger larger avalanches on the slopes below.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
This layer is getting harder for riders to trigger, but it is possible that it could still produce large, surprising avalanches. Triggering may be more likely when temperatures are above zero, or when they rapidly change in either direction.
This layer is a concern where there is a poor bond to underlying surface hoar crystals. This problem seems most pronounced in the Selkirks around Nelson and Kootenay Pass.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 28th, 2022 3:00PM
