Avalanche Forecast

Issued: Mar 6th, 2021 8:00AM

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

Andrew Jones,

Email

The new storm slab is reactive to skier triggering today. Extra caution is required in wind loaded areas.

Summary

Weather Forecast

Cloudy with sunny periods and isolated flurries with trace accumulation. Alpine temperature: High -7 C. Ridge wind west: 15-35 km/h. Freezing level: 1300m. A frontal system arrives sunday bringing another 9cm of new snow with cold temperatures (-8.0) and moderate to strong SW winds. A relatively stable and dry period begins Monday.

Snowpack Summary

Temperatures have begun to drop. At treeline,15cm of new snow sits atop a breakable crust and 10cm of moist snow. Localized extreme winds associated with the passing of a cold front increased snow loading near ridges. The February facet/ crust persistent weak layer is down 80-120cm.

Avalanche Summary

Warm temperatures created a moist avalanche cycle with several size 1.5-2.5 avalanches observed in the highway corridor. Early this morning the remote avalanche detection system at Rogers Pass showed 2 new avalanches, indicating a natural cycle is underway in the new storm snow.

Confidence

Problems

Storm Slabs

An icon showing Storm Slabs

15cm of new snow fell overnight and sits atop a breakable crust and 10cm of moist snow. Although temperatures are dropping, moisture in upper snowpack and locally strong winds will help increase the slab properties of this new dump.

  • Watch for fresh storm slabs on exposed lee slopes and open areas at all elevations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Wind Slabs

An icon showing Wind Slabs

Wind slabs in alpine start zones have been reactive to skier triggers this week. These slabs are buried under last night's snow, but they should not be forgotten. These slabs have a tendency to propagate on solar aspects where they sit on a crust.

  • Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Mar 7th, 2021 8:00AM