Avalanche Forecast North Columbia

Date Issued: Valid Until:

Avalanche Canada kdevine, Avalanche Canada

Avalanche Forecast

Tue Mar. 12th ยท 4:44PM

Alpine

Danger Ratings Considerable

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Moderate
Storm Slabs Storm Slabs

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Moderate

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Moderate

Below Treeline

Danger Ratings Low
Storm slabs may be reactive to human triggering, especially in wind loaded areas, and on steep, sun exposed slopes. Watch for signs of instability such as whumphing, cracking and recent avalanches.

Confidence

Moderate -

Weather Forecast

TUESDAY NIGHT - Cloudy with clear periods / northwest wind, 10-20 km/h / alpine low temperature near -10WEDNESDAY- Cloudy with sunny periods / west winds, 10-20 km/h / alpine high temperature near -10THURSDAY - Cloudy with sunny periods and isolated flurries / southwest winds 15-30 km/h / alpine high temperature near -8 / freezing level 1300 mFRIDAY - Mainly cloudy / southwest winds, 10-25 km/h / alpine high temperature near -6 / freezing level 1500 m

Avalanche Summary

On Tuesday, there were preliminary reports of natural and explosives triggered storm slab avalanches up to size 2.5 in the neighboring Glacier National Park region.On Monday, there were reports of human triggered storm slab avalanches up to size 1.5 and natural storm slab avalanches up to size 2.5.Reports on Saturday and Sunday include several natural and human triggered storm slab, loose dry and wind slab avalanches to size 1.5.On Friday, there were reports of human triggered storm slab avalanches up to size 2. There were also reports of a natural avalanche cycle to size 2.5 in the neighboring Glacier National Park region.

Snowpack Summary

20-50 cm of storm snow from the last week is sitting mainly on facets (sugary snow), as well as surface hoar (feathery crystals) in sheltered areas and a crust on sun exposed slopes. There are a two weak layers in the upper snowpack that were buried in mid and late January. These can be found approximately 60-120 cm deep. Both layers consist of surface hoar and may be associated with a crust on steep, south facing slopes. These weak layers have been most reactive at lower elevations. Avalanche occurrences on these layers have tapered significantly, however it may still be possible to trigger an avalanche on these layers in isolated areas such as steep cutblocks and large open glades.The lower snowpack is generally considered to be strong, except for shallow, rocky areas where the cold temperatures continue to facet (weaken) the snowpack.

Problems

Storm Slabs

Storm Slabs

20-50 cm of recent storm snow came in with moderate to strong southwest wind. Storm slabs are likely to be reactive, especially in wind loaded areas and on steep, sun exposed slopes.

Use caution around wind loaded pockets near ridge crests and roll-overs.Be cautious of sluffing in steep terrain.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2