Waterton Lakes National Park Avalanche Forecast

Mar 23rd, 2020 4:00PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Loose Wet.

New snow and continued wind will build slabs over the next few days. This is not the time to push the conditions as the healthcare system prepares to deal with COVID19.

Summary

Weather Forecast

10-20cm of snow is forecast arriving some time between Tuesday morning and Wednesday night. Winds will be moderate out of the west with a break on Wednesday afternoon. Freezing levels should remain at valley bottom with warmer temperatures and strong sunshine arriving on Thursday.

Snowpack Summary

A supportive crust exists on the surface that will be buried by incoming snow. The exception is straight north facing slopes where new snow will fall on settled powder in sheltered areas, and wind slabs everywhere else. The mid pack is strong and well settled. Basal instabilities haven't been seen in some time, but are likely lurking in thin areas.

Avalanche Summary

Avalanche activity in the last week has mainly been limited to loose wet avalanches up to size 2 on solar aspects with daytime warming. The exception was one loose avalanche that stepped down to a deep persistent slab in steep, rocky, unsupported terrain along the Akamina parkway.

Confidence

Timing of incoming weather systems is uncertain

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Likely

Expected Size

1 - 2

New snow paired with moderate west winds will form windslabs. The timing of the incoming precipitation is uncertain so keep a close eye on what the weather is doing over the next few days.

  • Use caution in lee areas. New snowfall mixed with wind loading is creating Wind Slabs.
  • Avoid avalanche terrain during periods of of strong sun, or heavy loading from new snow and wind.

Aspects:

North, North East, East, South East, South.

Elevations:

Alpine, Treeline.

Loose Wet

An icon showing Loose Wet

Likelihood

Likely

Expected Size

1 - 1.5

Sunny skies on Thursday means loose avalanches on solar aspects. Watch for the obvious signs of moist surface snow and pinwheeling, and avoid overhead hazard, especially where cornices are involved (think Mt. Bertha).

  • Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

Aspects:

East, South East, South, South West, West.

Elevations:

All elevations.

Valid until: Mar 26th, 2020 4:00PM