Avalanche forecast

Yukon

Mar 4 – 7, 2020Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
No rating
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Highlights

Last weekend's storm snow has been formed into widespread wind slabs at all elevations. New snow and wind Wednesday night into Thursday is expected to exacerbate this problem. Seek out wind sheltered terrain Thursday and Friday and avoid being below cornices.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2.5

    Wind is the name of the game right now. It's strong from the south Wednesday, but it's expected to shift to the east/northeast Thursday. 5 to 10 cm of snow over the next 24 hours should allow for the continued formation of fresh wind slabs which are expected to be sensitive to human triggering Thursday and Friday. Time to seek out the most wind sheltered spots you can think of. Give cornices plenty of space too, they are expected to be fragile.

Confidence

Low - Uncertainty is due to the extreme variability of wind effect on the snowpack. Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

We’re in for a bit of snow Wednesday night and then just high cloud & wind for the remainder of the forecast period.

WEDNESDAY NIGHT: Moderate south wind, freezing level at valley bottom, 5 to 10 cm of snow expected.

THURSDAY: Overcast, moderate to strong northeast wind, freezing level at valley bottom, trace of snow possible.

FRIDAY: Broken cloud cover, light variable wind, freezing level at valley bottom, no significant precipitation expected.

SATURDAY: Broken cloud cover, moderate southwest wind, freezing level at valley bottom, no significant precipitation expected.

Avalanche Summary

Our field team spotted some large natural avalanches on south/southeast facing slopes Tuesday that likely ran during the storm. The images in this MIN do a great job of showing the pattern of recent wind loading.

Snowfall Wednesday into the early hours of Thursday along with strong wind should allow for the continued formation of potentially touchy slabs.

Snowpack Summary

Strong south/southwest wind has resulted in extensive wind slab and cornice growth in open terrain at all elevations. Mild temperatures have likely allowed last week's 30-50 cm of powder to settle rapidly. On open south-facing slopes the storm snow sits above a sun crust.

At White Pass the snowpack is roughly 200 cm thick with a strong mid and lower snowpack. Thin snowpack areas to the east of White Pass may have a lower snowpack composed of sugary faceted grains, capped by a breakable melt-freeze crust and wind-affected snow.

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Regions covered