Avalanche Forecast Glacier National Park

Date Issued: Valid Until:

Parks Canada chris gooliaff, Parks Canada

Avalanche Forecast

Fri Apr. 26th ยท 8:00AM

Alpine

Danger Ratings Below Threshold

Treeline

Danger Ratings Below Threshold

Below Treeline

Danger Ratings Below Threshold
Loose Wet Loose Wet
Storm Slabs Storm Slabs

Alpine

Danger Ratings Below Threshold

Treeline

Danger Ratings Below Threshold

Below Treeline

Danger Ratings Below Threshold

Alpine

Danger Ratings Below Threshold

Treeline

Danger Ratings Below Threshold

Below Treeline

Danger Ratings Below Threshold

The danger will increase during the day with the powerful sun and warm temps. Cornices are large on ridge-crests and become fragile in the heat.

Weather Forecast

Increasing cloud today, with flurries tonight. Freezing levels (FZL) will rise to 2200m, with light S winds. Snow arrives tonight and continues Saturday, with 15-20cm expected. Winds will be moderate to strong from the SW during the snowfall. FZL will remain near 1400m. Clearing Sunday, with light NE winds and FZL rising to 1800m.

Snowpack Summary

Solar aspects will have a melt-freeze crust this morning. Isothermal snow lives below these surface crusts. Storm snow totalled over 50cm in the high Alpine last week, and N-NE aspects will have retained the driest snow. In certain locations, storm slabs have been reactive down to tree-line.

Avalanche Summary

Several loose, wet avalanches to size 2 were observed from both N and S aspects in the HWY corridor yesterday. A very large size 4 was observed at the south end of the park, starting as a size 2 storm slab and stepping down to glacial ice. Last Saturday, skiers triggered a size 2.5 slide on the Youngs Peak headwall.

Confidence

Problems

Loose Wet

Loose Wet

Another cool, clear evening last night formed a strong melt-freeze crust. The morning sun will break down the surface crust on E and S aspects, and initiating a loose wet cycle. Afternoon cloud may preserve the crust on W aspects.

  • Use extra caution on slopes if the snow is moist or wet.
  • Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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

Elevations: Treeline, Below Treeline.

Likelihood

Likely - Possible

Expected Size

1 - 2.5
Storm Slabs

Storm Slabs

50cm of storm snow has accumulated in the high alpine over the last 5 days. Recent storm slabs are susceptible to human triggering given the right terrain feature. Slabs seem most reactive on solar aspects, where they sit on a melt-freeze crust.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
  • If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Possible

Expected Size

1 - 2.5