Avalanche Forecast

Issued: Mar 1st, 2018 3:00PM

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

ghelgeson, Avalanche Canada

South Coast.

Wednesday's storm produced 20 to 40 cm accompanied by east wind, which has likely formed storm slabs in unusual locations. Keep a close eye on the effects of the strong sun Friday, it could initiate natural avalanche activity very quickly.

Summary

Confidence

Low - Timing or intensity of solar radiation is uncertain on Friday

Weather Forecast

There is potential for a few more centimeters of snow on Friday, and then we move into a high and dry period. No significant precipitation is expected for the foreseeable future. FRIDAY: Clear skies in the morning, cloud building throughout the day, freezing level around 600 m, light east wind, 2 to 5 cm of snow possible.SATURDAY: A few clouds, freezing level rising to around 1000 m, light northeast wind, no precipitation expected.SUNDAY: A few clouds, freezing level rising to around 1200 m, light west/northwest wind, no precipitation expected.

Avalanche Summary

No new activity to report from Wednesday, but we suspect that a small natural storm slab avalanche cycle occurred. On Tuesday storm slab avalanches up to 15 cm in depth were very touchy and sensitive to ski cutting, check out these two MIN reports here and here.

Snowpack Summary

The region picked up 20 to 40 cm of snow Wednesday and Thursday with moderate winds out of the east/southeast. This adds to the 50 to 70 cm that fell between Saturday and Tuesday. All of this snow rests on previously wind-affected surfaces and a sun crust on southerly aspects.A hard rain crust that extends into alpine terrain is buried about 60 to 120 cm deep. There are no substantial weak layers below the crust.Cornices have formed on many alpine ridgelines. They will become touchier as they grow in size, as temperatures rise, and as they are subject to the strong mid-winter sun on clear days.

Problems

Storm Slabs

20 to 40 cm of snow fell in the last 48 hours with winds out of the east, watch for slab formation in unusual locations. The recent snow is hiding slabs formed earlier this week. Periods of sun Friday may initiate natural storm slab avalanches.

Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.Caution with south facing slopes, periods of sun could quickly induce natural storm slab avalanches.Start with simple terrain and slowly step out as you gather information about the new snow.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Cornices

Large cornices have formed along ridgelines. Cornices are inherently unstable, unpredictable, and demand respect, especially if the sun is shining.

Give cornices a wide berth when traveling on or below ridges.Firm cornices may pull back into flat terrain at ridgetop if they fail.Avoid slopes when the solar radiation is strong, especially if they have large cornices overhead.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

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