Avalanche Forecast

Issued: Jan 3rd, 2020 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Wind Slabs, Deep Persistent Slabs and Loose Dry.

Jasper Snow Safety, Parks Canada

Jasper.

ICEFIELDS HIGHWAY WILL BE CLOSED SATURDAY JAN 4TH AT NOON FROM ATHABASCA FALLS TO SASKATCHEWAN CROSSING FOR AVALANCHE CONTROL, TENITIVE OPENING SUNDAY JANUARY 5TH AT 18:00. Check 511.alberta.ca for updates.

Summary

Weather Forecast

Tonight/tomorrow: Flurries. Precipitation 21cm Highs -7 Winds Moderate Westerly gusting to 70km/h.

Sunday: Snow up to 8cm accompanied by Moderate SW winds with Strong gusts. A cooling trend with day time highs of -14.

Tonight: Visit CAA's Mountain Weather Forecast for more specific details.

Snowpack Summary

Up to 25cm HST has fallen in the past 36 hours with an additional 30cm forecasted for tonight and into tomorrow. Buried surface hoar, present up to 2200m in sheltered areas. SSW winds continue to created new wind slabs on lee features at treeline and above. The bottom of the snowpack consists of pronounced facets, decomposing crusts and depth hoar.

Avalanche Summary

Minimal wind affect in BTL terrain that was observed today, A quick hasty test pit showed Sudden collapse results on the basal weakness

Concerning results from snowpack tests in Southern forecast region around Mount Wilson. Moderate to hard sudden planar results at treeline on the weak basal depth hoar/facet layers.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

This storm has come in with strong to extreme winds from the southwest.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Deep Persistent Slabs

This weakness could be triggered by large loads or from thin spots in the snowpack. This problem seems more pronounced at treeline where whumphing and cracks have been observed.

Watch for whumpfing, hollow sounds, and shooting cracks.
Be aware of thin areas that may propogate to deeper instabilites.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Loose Dry

An additional 30cm is expected tonight and through tomorrow. Caution in steep gullies and terrain traps where a small sluff could have large consequences.

Watch for terrain traps where small amounts of snow will acumulate into deep deposits.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Jan 4th, 2020 4:00PM