Avalanche Forecast - South Columbia   
Date Issued   Friday, 03 February 2012 7:32 PM   	   	
Valid Until    Saturday, 04 February 2012 11:00 AM

This is the first significant warm spell of the season and the snowpack is revealing its secrets, 
especially in alpine locations. Make conservative terrain choices as destructive avalanches are a 
real possibility.

Danger Rating: Saturday  

Alpine - 3 - CONSIDERABLE erous avalanche conditions. Careful snowpack evaluation, cautious 
             route finding and conservative decision making essential.
Treeline - 3 - CONSIDERABLE Dangerous avalanche conditions. Careful snowpack evaluation, cautious 
               route finding and conservative decision making essential.
Below Treeline - 2 - MODERATE Heightened avalanche conditions on specific terrain features. Evaluate 
                     snow and terrain carefully; identify features of concern.

	            Sunday 	            Monday
Alpine 	        3 - Considerable 	3 - Considerable
Treeline 	    3 - Considerable 	2 - Moderate
Below Treeline 	2 - Moderate 	    2 - Moderate

Confidence: Fair - Freezing levels are uncertain

Cornices

Large and unsupported cornices have formed and have become weak with warm alpine temperatures. 
Failing cornices are destructive by themselves and have the potential to trigger large avalanches 
on the slope below.

Deep Persistent Slabs

Deep persistent layers are re-awakening with recent warm temperatures. They are most likely to be 
triggered on solar aspects or by larger triggers such as cornice fall or an airborne sled.

Storm Slabs

Storm slabs may be susceptive to rider triggers. You're most likely to trigger a storm slab in steep 
and/or unsupported/convex terrain.

Travel and Terrain Advice

    Extra caution needed around cornices with current conditions.
    Be aware of the potential for full depth avalanches due to deeply buried weak layers.
    Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Avalanche Summary

Numerous natural cornice falls were reported, some of which triggered slabs on the slope below. Wet 
sluffing was also observed on sun-exposed slopes.

Snowpack Summary

Storm slabs up to 60cms thick have formed. They seem to be settling out quickly, but still show 
isolated sensitivity to rider triggers; particularly on steeper slopes and convex rolls. Wind slabs 
have formed on North through East slopes in the alpine and at treeline. Buried below seems to be a 
fairly settled mid-pack, with a couple of lingering layers. most notably the January 13th surface 
hoar/facet layer . Recent snowpack field tests have shown generally moderate results, including 
resistant planar shears. This layer is getting stronger; but it may become reactive with a larger 
load or warming. The average snowpack depth at 1700m is 2-3 m.Sun-exposed slopes as well as weak and 
large cornices are a concern with the current warming pattern.

Weather Forecast

Expect clear skies and light southerly winds for the entire forecast period. An inversion is also 
meant to dominate the region with alpine temperatures sitting at about 1.0'.