Avalanche Forecast

Issued: Mar 23rd, 2018 3:42PM

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

swerner, Avalanche Canada

South Rockies.

Strong winds are driving the alpine danger to CONSIDERABLE. Watch for whumphing and cracking below your feet and continue to make observations while gaining elevation towards alpine terrain.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

Saturday: Mainly cloudy. New snow 5-15 cm accompanied by strong southwest ridgetop winds. Alpine temperatures near -4 and freezing levels 1700 m.Sunday: Mix of sun and clouds with isolated flurries. Ridgetop wind strong from the West and freezing levels near 1400 m.Monday: Cloudy with some sunny periods and isolated flurries. Ridgetop wind strong from the southwest. Alpine temperatures near -8 and freezing levels 1300 m.

Avalanche Summary

Natural loose dry avalanches were reported on Friday from steeper slopes and terrain features.

Snowpack Summary

Up to 15 cm of new snow, accompanied by strong easterly winds in the beginning of the storm and now switching to the southwest are forming wind slabs on a variety of aspects. Forecast snow for Saturday will add to these totals and may initially have a poor bond to the underlying old snow surfaces which consist of crusts up to 2100 m and dry snow or surface hoar on north aspects above 2100 m. Snowpack testing on the March 15th surface hoar interface (down 20-40 cm on sheltered North aspects) has shown no significant results in the Barnes area. The mid-pack is is well consolidated. Deeper in the snowpack (50-80 cm down) a surface hoar buried mid-February may exist. This interface is dormant. Digging towards the bottom of the snowpack you'll find a combination of crusts and facets that are reportedly widespread.

Problems

Wind Slabs

Changing winds from East to West continue to be strong, redistributing the new storm snow onto most aspects. Wind slabs will likely be reactive to skier/rider triggers. Loose dry avalanches may occur from steeper terrain features.

Avoid large slopes with thin-thick snow coverage and convex features.Use caution in lee areas in the alpine and tree line.Watch for signs of instability such as whumpfing, or cracking.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 24th, 2018 2:00PM