Avalanche Forecast

Issued: Mar 21st, 2018 4:54PM

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

swerner, Avalanche Canada

South Rockies.

Pay close attention to how the new snow is bonding to the old snow surfaces, especially where it sits on surface hoar and buried crusts. If you receive more than 20 cm in your local riding area by the afternoon bump the danger to CONSIDERABLE.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Thursday

Weather Forecast

Thursday: 5-10 cm expected accompanied by strong easterly winds. Freezing levels near 1500 m. Friday: Mainly cloudy with up to 5 cm of new snow. Alpine temperatures near -6 and freezing levels dropping to 1300 m. Ridgetop winds light with strong gusts from the southwest.Saturday: Mainly cloudy with a trace of new snow. Alpine temperatures near -9 and freezing levels 1300 m. Ridgetop winds light from the southwest.

Avalanche Summary

No recent avalanche activity has been reported on Wednesday. Avalanche hazard will be on the rise with forecast snow and wind.

Snowpack Summary

Recent storm snow accumulations total 30-40 cm of low density fluff. Forecast snow for Thursday will add to these totals and likely have a poor bond to the underlying snow surfaces which consist of crusts, dry snow or surface hoar on north aspects above 1500 m. Deeper in the snowpack (50-80 cm down) a weak layer of surface hoar buried mid-February may exist. This interface is dormant, but could wake up with a heavy load like a cornice fall, human triggers from a thin, shallow area on the slope or a rapid warm up. Digging towards the bottom of the snowpack youll find a combination of crusts and facets that are reportedly widespread.

Problems

Storm Slabs

The new snow will likely have a poor bond to the plethora of old snow surfaces. Especially where it sits on the March 18th crust and surface hoar. Natural dry loose avalanches will likely run on steeper slopes and terrain features.

Avoid large slopes and convex features.Use caution in lee areas in the alpine and tree line, especially south / west facing slopes.Watch for signs of instability such as whumpfing, or cracking.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 22nd, 2018 2:00PM