Avalanche forecast

Jasper

Apr 16 – 17, 2019Parks Canada
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Archived · expired 7 years ago

Avalanche danger

Thu
Fri
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low

Highlights

The pockets of windslab in the alpine could be triggered by the weight of a skier, expect them to be most reactive where they sit on a crust.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Pockets of windslab can be found in alpine lees (more prevalent in the northern parts of the region). A significant snow event forecasted for late Thursday and Friday will build fresh reactive storm/wind slabs.

  • Persistent Slabs

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

    Evidence from recent snowpack tests and whumphing would suggest that a weak layer of facets persists down 20-50cm in some areas. This layer will likely become reactive with loading from forecasted snow later in the week.

Weather Forecast

On Wednesday a warm front will pass over us, followed by a costal low with precipitation and strong winds on Thursday-Friday.

Wednesday: Cloudy with sunny periods and isolated flurries. Treeline temperature: Low -5, High -3 C. Ridge Light (gusting strong) from the West. Freezing level: 2000 metres.

Snowpack Summary

Above treeline 10cm of settling snow sits on a variety of crusts. Above 2200m on Northerly slopes, a more winter like snowpack can be found, with pockets of windslab, a peristent weak layer down 20-50cm and a facetted mid and lower snowpack which is weak in shallow areas.

Avalanche Summary

There was isolated natural windslab activity observed during last weekends wind/snow event. The mid march PWL continues to produce whumphing in shallower snowpack areas and on moraine features, indicating unstable snow below.

Confidence

Regions covered