Jasper National Park Avalanche Forecast
Apr 30th, 2019 5:19PM
New snow may hide previously obvious windslabs on solar aspects. Facets and upper snowpack crusts persist on all aspects.
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.
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.
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.
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.
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.
Valid until: May 1st, 2019 4:00PM