Avalanche Forecast Jasper National Park

Date Issued: Valid Until:

Parks Canada jasper snow safety, Parks Canada

Avalanche Forecast

Tue Apr. 30th · 5:19PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Persistent Slabs Persistent Slabs
Wind Slabs Wind Slabs

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low

New snow may hide previously obvious windslabs on solar aspects. Facets and upper snowpack crusts persist on all aspects.

Weather Forecast

Snowfall arriving. Forecast models disagree on amounts(5-35cm by the weekend), but align more on winds (light-moderate Westerlies) and freezing levels.

Weds: Cloud, light snow developing. Freezing level 1600m, treeline high -4, light-mod Westerlies.

Thur: Overnight snow eases to flurries. Freezing Level 1900m, Treeline High -2. Light winds.

Snowpack Summary

Wind Slabs lee to N winds linger over sun crusts on solar aspects in the alpine, and in wind-prone treeline areas. Low density cold snow remains in wind/sun sheltered terrain, particularly in Easterly ranges and near the Icefields. A buried facet layer on shady alpine slopes remains a concern; giving easy/sudden test results just SW of our region.

Avalanche Summary

No patrol Tuesday.  To the South of our region (Bow Summit), 2 large (size 2 - 2.5) persistent slabs were remotely triggered on alpine SW aspects Tuesday.  On Sunday, 1 Large (sz 2.5) Persistent slab was observed in the Maligne Range on an East aspect, in convex alpine terrain.

Confidence

Forecast snowfall amounts are uncertain

Problems

Persistent Slabs

Persistent Slabs

Cool temperatures mean little change for this problem; triggering remains possible in the alpine. Crusts in the upper snowpack, and deeper facet layers warrant further investigation.

  • Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.
  • Watch for signs of instability such as recent avalanche activity, and whumpfing/cracking underfoot.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 3
Wind Slabs

Wind Slabs

Slabs lee to previous N winds may still fail on a persistent interface (facets over a suncrust) down 15-40cm.

  • Keep an eye out for reverse loading created by N-NE winds.
  • Recent snow may be more sensitive to human triggering on solar aspects where it sits on sun crust

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2