Avalanche Forecast

Issued: Mar 7th, 2021 4:00PM

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

Avalanche Canada MBender, Avalanche Canada

Email

 Wind slabs at upper elevations are the main concern. Spotty flurries may develop overnight Sunday where parts of the region may receive 10 cm+ and other parts just trace amounts. 

Summary

Confidence

High - The snowpack structure is generally well understood.

Weather Forecast

SUNDAY Night: Cloudy with scattered flurries, accumulation 1-5 cm. Light to moderate southwest wind. Alpine high temperatures around -8 C. Freezing level at valley bottom.

MONDAY: Mix of sun and cloud. Light west and southwest wind. Alpine high temperature -4. Freezing level 1400 m.

TUESDAY: A mix of sun and cloud. Light west and southwest wind. Alpine high temperature -5. Freezing level 1400 m.

WEDNESDAY: Cloudy with sunny breaks and isolated flurries. Light to moderate northwest wind. Alpine high temperature -6. Freezing level 1300 m.

Avalanche Summary

Reports from Saturday show a few natural wind avalanches to size 2 on northerly aspects above 2100 m. Most reports highlighted primarily loose dry and loose wet avalanches from steep terrain facing the sun to size 1 and 1.5.

Warm sunny weather between Wednesday and Friday resulted in a widespread cycle of wet loose avalanches on sun-exposed slopes. These were mostly small (size 1-1.5), but a few large (size 2.5) wet avalanches were also reported. Heating also caused some cornice and ice falls. Clouds and cooling temperatures will heal these problems. 

.

Snowpack Summary

About 15 cm of new snow over Friday night accumulated above moist and crusty interfaces that formed during the recent warm up. Some deeper accumulations can be expected in lee terrain features. High shaded terrain will have a mix of soft snow and some old buried wind slabs. 

The lower snowpack has strengthened over the past week as previous persistent weak layers have become unreactive. The main layers that we had been tracking were a layer of facets that was buried in mid-February (60-100 cm deep) and a layer of surface hoar and/or crusts that was buried in late January (80-120 cm deep).

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.

Problems

Wind Slabs

An icon showing Wind Slabs

 Recent new snow and wind has formed new wind slabs at upper elevations. 

Aspects: North, North East, East, South East, West, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 8th, 2021 4:00PM