Waterton Lakes National Park Avalanche Forecast

Mar 9th, 2020 4:00PM

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 Wet.

Wind is the word of the day, with ridgetop winds forecast to reach 100km/h on Tuesday forming new slabs up high.

Summary

Weather Forecast

Tuesday: Mainly cloudy with isolated flurries. Temperatures and west winds increasing through the day up to 110km/h at ridgetop and a high of -6.

Wednesday: Sun and cloud with flurries and a cooling trend through the day with moderate NW winds.

Thursday: Increasing cloudiness through the day with flurries, winds becoming calm in the evening.

Snowpack Summary

Surface snow is moist on solar aspects during the heat of the day. 20cm settling storm snow is being blown into windslabs by moderate SW winds, with windward ridgetops in the alpine stripped to rock. This sits on previous windslabs and crusts. The midpack is strong, though weaker basal facets still lurk in thin areas.

Cornices are large and looming.

Avalanche Summary

Surrounding areas have reported small loose dry and storm slab (especially in the alpine) avalanches in the new snow failing naturally in steep areas and with skier traffic.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Likely

Expected Size

1 - 2

20cm of recent snow will continue to form slabs in the alpine and treeline with 100km/h winds on Tuesday. Pay particular attention to slopes above you if the clouds part- the March sun is packing a punch!

  • 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:

Alpine, Treeline.

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 Wet

An icon showing Loose Wet

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 12th, 2020 4:00PM