Glacier National Park Avalanche Forecast

Issued: Apr 10th, 2021 8:00AM

Fri Apr 9th Current Conditions
Alpine Considerable Treeline Moderate Below Treeline Low
Sat Apr 10th 2 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low
Sun Apr 11th 3 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Cornices.

Winter weather maintains its grip on Rogers Pass. The refresh of powder also brings a storm instability that requires careful terrain selection to avoid heavily loaded areas.  Watch for loose avalanches if the sun comes out.

Summary

Weather Forecast

Moderate snow will continue today with 7cm of accumulation.  Alpine high will reach -9, W winds 25-45km/h, freezing level at 1000m. A high pressure system builds later this evening with a return to clear skis and cool overnight temps of the coming week. Sun and daytime warming will bring spring conditions. Freezing levels rise sharply on Wednesday.

Snowpack Summary

15cm of new snow fell overnight with strong S winds. Storm/ wind slabs cover a variety of old surfaces: settled powder on sheltered alpine N aspects, wind slabs/ wind pressed surfaces in exposed areas, a sun crust on solar aspects, and spring melt/freeze crust below treeline. Cornices are large and fragile. The March 18 crust is buried ~80-100cm.

Avalanche Summary

A field crew was able to ski cut several small size 1.0 thin wind slabs while descending Macdonald West Shoulder #4. Two large glide releases (size 4 and size 3) released earlier this week in the highway corridor off of Mt Tupper.

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs

Likelihood

Likely

Expected Size

1 - 2.5

15cm of new snow with strong winds and ongoing precipitation has created a storm instability at higher elevations. Wind loaded areas will be more susceptible to triggering. New snow conceals existing wind slabs that can still be triggered.

  • Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Cornices

An icon showing Cornices

Likelihood

Possible

Expected Size

1.5 - 3

Natural cornice failures have been observed over the past several days. Cornice problems are notoriously difficult to forecast for. Keeping distance between cornices and associated runout zones is good strategy for safe spring travel.

  • Extra caution needed around cornices with current conditions.

Aspects:

North, North East, East, North West.

Elevations:

Alpine.

Valid until: Apr 11th, 2021 8:00AM

Forecast Trend

The latest forecast danger ratings, broken down to elevation. See how an elevation is trending.