[MCR] Raft Peak - Trophy Range South Cariboos

[Public Mountain Conditions Report]

Raft Peak - South Cariboos

This conditions posting is a day or so late but I felt that the  
observations are still relevant.

Skied at the headwaters of Molliet Creek on Monday Dec 13th, the day  
after heavy storm snow loading in this region. Total storm snow  
amounts from the weekend are up to 40 cm at tree line, bringing the  
snowpack height to about 140 cm at TL in this area. Air temperature  
at 2100m mid-day was -5.0c
Extensive west to east (traditional) loading pattern from moderate to  
strong winds last Sunday. Wind effect occurred above tree line and in  
open areas below tree line producing hard slabs on windward slopes  
and soft slabs in leeward terrain above 1900m.

Storm snow was settling rapidly with widespread observations of  
"settlement cones" around the base of trees. These are small  
fractures that appear around basal branches of conifer trees, this  
can be due to the rapid addition of snow "load" on softer weaker snow  
below.
I did not spend time conducting detailed snowpack observations such  
as compression tests. Ski cutting on short steep convex features in  
treed terrain did not produce fractures and I did not experience any  
"whumpfing".

The "Fro" bowl ran size 3 with debris close to the normal run out.  
This natural slab avalanche occurred "mid-storm" as the fracture line  
was already partially filled in and the toe of the debris had snow  
accumulation on it.  This avalanche was in skiable terrain, north  
aspect between 2100 and 1650m. The neighbouring bowl "Carolines" also  
cleaned out but not as extensively with debris only reaching mid- 
path. The depth of the fractures were  40cm on average by "eye  
balling it". There were also a few size 1.5 and 2.0 natural storm  
snow releases below rock bands in steep un-skiable north facing  
terrain at tree line elevations.  I observed one size 2.0 avalanche  
on a north aspect at least 45 degrees that ran to the ground in rocky  
un-skiable terrain at about 2000m, this was very isolated.

The storm snow has significantly improved coverage over ground  
obstacles below tree line. Ski quality was good in protected areas.

The new load on softer weaker snow below may still just be waiting  
for a "human" trigger in specific terrain features such as steep lee  
tree line and alpine terrain and skiable un-supported terrain at all  
elevations and aspects.

Dana Foster Ludwig
Ski Guide
Snowy Mountain Alpine Tours
Blue River - Clearwater BC
P 250 674 2988
www.snowymountain.ca




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