Avalanche Forecast

Issued: Mar 4th, 2021 4:53PM

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

Lisa Paulson,

Email
http://www.pc.gc.ca/apps/links/goto_e.asp?destination=

A Special Avalanche Warning is in effect, click here.

Beautiful day today! Expect another crust on solar aspects. Start and finish early, expect the hazard to increase as the day warms or with prolonged solar input.

Summary

Weather Forecast

A ridge of high pressure continues to bring mainly sunny skies, rising temperatures and 30-80km/hr winds from the South West. The freezing level is expected to rise to ~2000m on Friday with valley bottom temperatures reaching +10. Expect increasing cloud Friday afternoon with light flurries overnight and into Saturday.

Snowpack Summary

Strong SW winds have scoured exposed slopes and formed wind slab in alpine lee areas and open tree line slopes.  Expect a new surface crust on solar aspects. In the Little Yoho Valley, the height of snow at tree line is ~280cm and does not seem to have the same Persistent Slab problem as Banff and Kootenay region.

Avalanche Summary

Sunny skies and warm temperatures will have an effect on solar aspects, triggering loose wet avalanches and increasing the sensitivity of wind slabs & cornices.  Many natural and explosive triggered avalanches to size 3 in the Banff region in the past week.  Two close calls in the Simpson area of Kootenay Park last weekend.

Confidence

Timing of incoming weather systems is uncertain on Friday

Problems

Loose Wet

An icon showing Loose Wet

Clear skies and warm temperatures are forecast for Friday. The March sun is strong and will pack a punch on solar aspects. Steep, rocky terrain will be the most susceptible.

  • Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.
  • Avoid ice climbs that are exposed to steep rocky terrain on solar aspects.

Aspects: South, South West, West.

Elevations: Treeline, Below Treeline.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs

Sustained strong winds from the SW have blown the available snow into hard wind slabs in open areas. These can be quite deep in immediate lee areas.

  • Watch for shooting cracks or stiffer feeling snow. Avoid areas that appear wind loaded.
  • Pay attention to overhead hazards like cornices which could trigger slabs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2.5

Valid until: Mar 5th, 2021 4:00PM