Avalanche Forecast

Issued: Feb 25th, 2014 8:46AM

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

triley, Avalanche Canada

Northwest Inland.

Forecast sun and high freezing levels may increase the danger from loose wet avalanches and avalanches stepping down to the deeply buried weak layer.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Wednesday

Weather Forecast

Overnight and Wednesday: Clear overnight with moderate Southerly winds and alpine temperatures near -15. Mostly sunny during the day with light South winds and no precipitation.Thursday: Sunny with moderate Northerly winds and temperatures of about -5 in the alpine.Friday: Mostly sunny with strong Northerly winds and cooler temperatures.

Avalanche Summary

Several small natural and rider triggered wind slabs were observed on Sunday. Loose snow sluffing was also reported on steep sheltered slopes. Forecast sunshine and warmer temperatures this week may be enough to make the mid February persistent weak layer become reactive.

Snowpack Summary

Outflow winds picked up late on Saturday and have likely resulted in reverse loading in exposed terrain. 35-90 cm of settled storm snow overlies a variety of old surfaces including weak facets, surface hoar (more predominant at tree line and below tree line elevations), a scoured crust, wind pressed snow, or any combination of these. Whumpfing, cracking, and reports from the field indicate a very poor bond between the new snow and these old surfaces. Recent snowpack tests give easy or moderate "pops or drops" shears on this persistent weakness and show potential for wide propagation. A lack of activity on this layer is likely because the overlying snow has not settled into a slab due to the recent cold temperatures.

Problems

Persistent Slabs

The mid February persistent weak layer is down between 35 and 90 cm. Forecast solar radiation and warming temperatures could make this problem more reactive.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Use conservative route selection, stick to moderate angled terrain with low consequence.>Minimize exposure to sun exposed slopes when the solar radiation is strong.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 4

Wind Slabs

Outflow winds may have redistributed some of the recent storm snow and formed dense wind slabs in unusual places.

Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Feb 26th, 2014 2:00PM