Avalanche Forecast

Issued: Mar 22nd, 2013 10:44AM

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

jfloyer, Avalanche Canada

South Rockies.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain

Weather Forecast

Synopsis: Generally very fine weather with cool overnight temperatures and warm, sunny days.Saturday: Cloud lingering, but also some clear breaks. Freezing level 1700 m. Light northerly winds.Sunday and Monday: Clear and sunny. Freezing level around 1600 m. Light southwesterly winds.

Avalanche Summary

A couple of large natural avalanches were reported from northeast of Sparwood that likely ran on Wednesday or Thursday on the buried rain crust. On Friday, a few cornice releases were observed and sluffing was noted in the new snow on steep terrain.

Snowpack Summary

Approximately 40-70 cm recent storm snow sits on top of a buried rain crust that exists up to around 2100 m. In areas near Sparwood, the new snow bonded poorly to this crust, and a few large avalanches were observed that likely released on this layer. In the North Elk Valley, the bond at the crust was reported to be good. Generally, this interface has now become stronger, and is unlikely to release due to the weight of a person alone. However, a large trigger, such as a cornice fall, or an airborne sledder, could potentially trigger a large avalanche on this layer in steep terrain. Recent wind slabs exist in the immediate lee of ridge lines and terrain features. Cornices are large and fragile. Mid and lower snowpack layers are generally well-settled.

Problems

Cornices

Do not travel on slopes that are exposed to cornices overhead.>Give cornices a wide berth when travelling on ridges.>

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

2 - 5

Storm Slabs

Recent storm snow could release on a buried crust on steep, aggressive terrain, or where it has been blown into wind pillows behind ridges.

Avoid steep slopes with convexities or areas with a thin or variable snowpack.>Watch wind loaded features.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Loose Wet

Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 23rd, 2013 2:00PM