Avalanche Forecast
Issued: Apr 22nd, 2022 4:00PM
The alpine rating is Wind Slabs and Cornices.
, the treeline rating is , and the below treeline rating is Known problems includeWe are getting back into a seasonal spring trend with cool nights, warm days, and highly variable snow conditions with elevation and aspect changes. Be on the lookout for signs that suggest unstable snow.
Summary
Confidence
Moderate - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.
Weather Forecast
FRIDAY NIGHT: Partly cloudy, 10-20 km/h northwest wind, alpine low temperature -8 C, freezing level falling to valley bottom.
SATURDAY: Mix of sun and cloud with isolated flurries, accumulation trace to 5 cm, 5-15 km/h northwest wind, alpine high temperature +1 C, overnight freeze and daytime freezing level rising to 2100 m.
SUNDAY: Clear skies with no precipitation, 15-25 km/h southwest wind, alpine high temperature +6 C, overnight freeze and daytime freezing level rising to 2300 m.
MONDAY: Mix of sun and cloud with isolated flurries, accumulation to 5 cm, 20-30 km/h southwest wind, alpine high temperature +2 C, overnight freeze and daytime freezing level rising to 2100 m.
Avalanche Summary
A few small (size 1) skier-triggered slabs occurred Thursday, about 30 cm deep and sliding on the crust below. Additionally, A handful of wet loose avalanches to size 2 were observed on west aspects to 2350 m.
Wednesday saw small storm slab avalanches triggered in the west of the region at alpine terrain on north to east aspects, where they received up to 40 cm of recent snow. Otherwise, wet loose avalanches were triggered during the heat of the day.
Please consider posting your observations to the Mountain Information Network to supplement our data stream and help fellow recreationists.
Snowpack Summary
Around 10 to 20 cm of snow accumulated since Tuesday in most of the region with up to 40 cm in localized areas and such as near the Bugaboos and east side of Glacier National Park. Locally deeper deposits may be found in lee terrain on shaded slopes at treeline and alpine elevations from southwest wind. Sun has moistened the snow up to 2400 m and on all sun-exposed slopes. A consolidated and moist snowpack exists below treeline. At ridge top, remember that cornices are large and looming at this time of year.
Around 100 to 200 cm deep, faceted grains persist around a hard melt-freeze crust from early December. There's uncertainty on if and when this layer will wake up, but it could during the next intense or prolonged warm-up.
Terrain and Travel
- Carefully evaluate steep lines for wind slabs.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
Problems
Wind Slabs
Use caution entering steep, lee terrain features below ridges, where wind slabs could be found.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Cornices
Cornices are large and fragile. The likelihood of them failing increases with each day of warming. Any release could be catastrophic.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 23rd, 2022 4:00PM