Avalanche forecast

Purcells

Apr 23 – 24, 2022Avalanche Canada
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Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low
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Highlights

With a sunny spring day, check for good overnight re-freeze and make sure to be off slopes before they turn mushy or wet.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    2–3

    Cornices are large and fragile. The likelihood of them failing increases with each day of warming. Any release could be catastrophic.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2

    Use caution on sun-exposed slopes when the sun is shining. Relatively warm air and sun can pack a punch, causing loose wet avalanches that may entrain recent snow and travel far.

    Keep in mind that any snowpack can quickly loose strength when heat penetrates to deeper layers for the first time. Check for good overnight recovery - avoid slopes that do not get an overnight re-freeze. 

Confidence

High - Uncertainty is due to the timing or intensity of solar radiation and its effect on the snowpack.

Weather Forecast

SATURDAY NIGHT: Mostly clear, 10 km/h northwest wind, alpine low temperature -8 C, freezing level falling to valley bottom.

SUNDAY: Sunny with afternoon cloudy patches, 15-25 km/h southwest wind, alpine high temperature +6 C, freezing level rising to 2500 m.

MONDAY: Mix of sun and cloud with isolated flurries, accumulation to 5 cm, 20-30 km/h southwest wind, alpine high temperature +4 C, poor overnight re-freeze with freezing level hovering around 2200 m.

TUESDAY: Wet flurries, 5-10 cm. Light west wind, alpine high temperature +1 C, daytime freezing level rising above 2200 m.

Avalanche Summary

A few small (size 1) skier-triggered slabs occurred Thursday, about 30 cm deep and sliding on a crust. 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

Sun and warm temperatures have moistened the snow up to 2400 m and on all sun-exposed slopes. Cold, dry snow persists on more north-facing and shaded aspects in the alpine and high treeline; in these areas use caution entering steep, lee terrain features below ridges, where wind slabs could be found. At ridge top, remember that cornices are large and looming.

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

  • Make observations and assess conditions continually as you travel.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Regions covered