Waterton Lakes National Park Avalanche Forecast

Mar 12th, 2020 6:59AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs, Cornices and Loose Dry.

Updated 08:00 am on Friday:

An unexpected but welcome 15-20cm of new snow has fallen in the park since yesterday, adding to our windslab problem. Blizzard like conditions are expected for the weekend, elevating the hazard rapidly.

Summary

Weather Forecast

Clear skies on Thursday morning making way to building clouds and afternoon flurries. The weekend is setting up for an intense upslope spring storm with blizzard like conditions.

Snowpack Summary

Up to 20cm of new snow from convective flurries yesterday overlies wind affected surfaces including windslab and crusts from the extreme wind event earlier in the week. The midpack is strong, though weaker basal facets still lurk in thin areas.

Cornices are large and looming.

Avalanche Summary

Surrounding areas have reported Natural and explosive triggered storm slab avalanches to size 2 in alpine features on Wednesday.

Confidence

Intensity of incoming weather systems is uncertain on Saturday

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Likely

Expected Size

1 - 2

15-20cm of low density snow from yesterday has formed new windslabs in the alpine with moderate NW winds over previous slabs form the extreme wind event earlier this week.

  • Use caution in lee areas. Recent wind loading has created wind slabs.
  • Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects:

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

Elevations:

All elevations.

Cornices

An icon showing Cornices

Likelihood

Possible - Unlikely

Expected Size

1 - 2.5

Cornices are large in the park, and present the additional hazard of potentially triggering deep persistent weak layers. Give them a wider berth than you think, whether you are considering travelling on the ridge above or slope below.

  • Give cornices a wide berth when travelling on or below ridges.
  • Pay attention to overhead hazards like cornices which could trigger the deep persistent slab.

Aspects:

North, North East, East, South East.

Elevations:

Alpine, Treeline.

Loose Dry

An icon showing Loose Dry

Likelihood

Possible

Expected Size

1 - 1.5

Be mindful of overhead hazard if the sun makes an appearance, especially in steep rocky terrain.

  • Avoid ice climbs exposed to steep rocky terrain on solar aspects during the middle of the day.
  • Avoid steep Southerly aspects.

Aspects:

South East, South, South West.

Elevations:

All elevations.

Valid until: Mar 15th, 2020 4:00PM