North Columbia Avalanche Forecast

Mar 26th, 2020 4:00PM

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

Expect the danger to be one-step higher in localized areas that receive 20+ cm of new snow prior to Friday evening.

Storm slabs will begin to form as the new snow amounts increase throughout the day and will be most reactive on leeward slopes.

Summary

Confidence

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

Weather Forecast

THURSDAY NIGHT: Snow; 5-10 cm, moderate west winds, alpine low -4 C, freezing level 700 m.

FRIDAY: Snow; 5-10 cm, moderate to strong west winds, alpine high 0 C, freezing level 1400 m.

SATURDAY: Snow; 5-15 cm, strong southwest winds, alpine high 1 C, freezing level 1500 m.

SUNDAY: Snow; 5-10 cm, moderate southwest winds, alpine high 1 C, freezing level 1500 m.

Avalanche Summary

There are currently no professional operations reporting in this region and the data stream is very limited.

Avalanche activity is expected to increase throughout the weekend as new snow amounts increase.

Snowpack Summary

NOTE:We are no longer receiving any professional snowpack observations in this region. The snowpack summary below is based on our most recent observations and weather data.

The recent snow sits on a variety of snow surfaces, consisting of sun crusts, hard wind-affected snow, and soft faceted snow. There have also been reports of surface hoar forming on sheltered, shady slopes. See this MIN for a helpful illustration from nearby Glacier National Park. It will be important to track the depth, cohesiveness, and bond of the new snow to these various old snow surfaces across aspects and elevations where you're travelling.

Cornices are large and looming. Two layers of buried surface hoar may be found buried 20-40 cm deep (March 10) and 60-120 cm deep (February 22). Though there is a low likelihood of triggering an avalanche on these layers, the consequences of doing so would be high. Avalanche activity on the Feb 22 layer was last reported on March 8th.

Terrain and Travel

  • Be alert to conditions that change with aspect and elevation.
  • Watch for fresh storm slabs building throughout the day.
  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Be aware of the potential for large avalanches due to the presence of buried surface hoar.

Problems

Storm Slabs

An icon showing Storm Slabs

Likelihood

Possible

Expected Size

1 - 2

Storm slabs will begin to form as the new snow amounts increase throughout the weekend. Wind-affected slopes will be the first to become reactive to human triggers.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Valid until: Mar 27th, 2020 5:00PM