[MCR] Rogers Pass

[Public Mountain Conditions Report]

We skied in Rogers Pass January 24-29. When we left yesterday the  
primary concern were windslabs in alpine and exposed treeline areas.  
We went to Lookout Col and observed several natural avalanches  
yesterday to size 2 that were running out of steep lee zones in the  
alpine. Cornices were also large in this area.

We also still had significant concerns about deep instabilities in  
the alpine. We continue to limit exposure to large alpine features,  
especially if cornices overhang them. Although we felt the  
probability of a large avalanche occurring was reasonably low, if a  
large trigger like a cornice fall were to hit a slope and cause a  
deep layer to fail the consequences of being in the way of the  
resulting avalanche were enormous and probably unsurvivable.

Probably the best information we can give right now is a synopsis of  
where large avalanches ran during last week's avalanche cycle. We had  
mediocre visibility and there is a lot of snow on the old debris but  
this is what we saw:

Connaught
Looks like all the Cheops paths went big and in some places ran into  
the forest on the other side of the valley (hitting the normal  
uptrack). A couple of medium sized trees had been snapped off.

Grizzly slide path did not go big. Frequent Flyer did not look like  
it went big, although perhaps it went very early in the storm and the  
debirs is well covered by subsequent snowfalls. If not then this  
place is disconcerting.

Loop Brook
None of the paths affecting the initial approach up the creek ran  
big. We observed a size 2 loose snow avalanche off Mt Green that did  
not run past the top of the fan and did not trigger a slab.

Upvalley no major activity was noted on the Lily or Bonney sides  
except for large fracture lines below the n face of Bonney that ran  
onto the glacier. The moraines have not slid.

Asulkan
Big stuff here. A size 4+ off of Mt Jupiter ran into the Mousetrap. A  
size 4 ran out of the northern half of the Ravens into the Mousetrap  
(the southern half still seems to be there). A size 3+ ran out of the  
basin west of Lookout Col but I'm not sure if it made it all the way  
to the Mousetrap. Only about 10% of the start zone in this basin has  
released, there is a lot more snow up there. I calculated that there  
is at least 30,000 tonnes of debris in the Mousetrap from all these  
avalanches. There is a huge fracture line down to the ice in the  
Forever Young couloir, not sure how far it ran. No debris in the Tree  
Triangle.

Illecillewaet
A size 4 ran from the base of Sir Donald's west face, took out the  
slopes on the moraine below the w face, and ran to valley bottom. It  
broke a few trees. The east face of Glacier Crest had old thick  
fracture lines. Otherwise we just saw recent windslab activity to  
size 2 with about 30 cm thick fracture lines.

Hope that helps.

Mark Klassen
Mountain Guide
www.facebook.com/alpinism


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