Avalanche Canada cgarritty, Avalanche Canada

Lizard Range and Flathead Avalanche Forecast

Mar 25th, 2020 4:00PM

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

Limited observations are keeping forecast confidence low. Recent snow is expected to remain reactive to triggering on Thursday.

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

Wednesday night: Becoming clear. Light to moderate northwest winds.

Thursday: Sunny. Light to moderate west or southwest winds increasing over the day. Alpine high temperatures around -6.

Friday: Mainly cloudy. Light to moderate southwest winds. Alpine high temperatures around -5.

Saturday: Mainly cloudy. Light to moderate southwest winds. Alpine high temperatures around -4.

Avalanche Summary

No new avalanches were reported from Tuesday's storm, but observations have been minimal. The new snow is expected to remain reactive over the near term, especially on steeper south facing slopes and in areas where wind loading has occurred or will occur.

Snowpack Summary

About 20 cm of new snow accumulated during Tuesday's storm. The new snow likely sits above a melt-freeze crust on sun-exposed slopes and on previously wind-affected snow in other areas, so new slabs may take some time to bond to these surfaces.

A layer of faceted grains overly a melt-freeze crust from early February. This layer currently sits 30 to 60 cm below the surface. This layer remains dormant and has not produced a reported avalanche for about a week.

The base of the snowpack may contain a weak layer of faceted grains that are most prominent in shallow rocky start zones with a snowpack depth of 150 cm or less.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Make conservative terrain choices and avoid overhead hazard.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible-Likely

Expected Size

1 - 2

Increasing southwest winds are expected to move Tuesday's snow into new wind slabs on leeward slopes, particularly near ridgetop.

Aspects:

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

Elevations:

Alpine, Treeline.

Loose Wet

An icon showing Loose Wet

Likelihood

Likely

Expected Size

1 - 2

New snow accumulations exposed to strong sunshine will be increasingly likely to shed from steep slopes on Thursday. This may occur naturally or with a human trigger.

Aspects:

South, South West.

Elevations:

All elevations.

Valid until: Mar 26th, 2020 5:00PM