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Colfax conditions (???)


Panos

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basing your avi assessment on angle of slope is crazy. There are tons of more variables than simply angle, especially in the PNW. I have seen snow stick to pan dome falls and that ice climb is 80 degrees. Slabs can build on 45 degree slopes. Thin slabs can build on 60 degree slopes due to the water content of the snow. A thin slab fracturing will take you for a ride and the consequences of a avalanche often depend on where the avi stops. (think cliff band, crevasses, or ditch or ravine or crevasse that will fill in ontop)

 

the only thing going for roman wall (as far as avi probability) is that it is usually the windward side and therefore usually lacks the heavy wind loading. But if the winds comes from the north?

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Also wet slabs can cut out a few dgs lower than the 30dg< non-wet slab dg angle.

 

OK, I'm no avalanche expert by any means. But, what is this magical 30dg number you keep throwing about? Are you saying dry slab avalanches never occur under 30dg? I've never read that. I've always heard that the range was more like 25dg-55dg. I also got the impression that avalanches science was in its infancy and avalanche prediction was somewhat mysterious, and that "there are no avalanche experts."

 

But you seem to know quite a lot, and seem pretty certain. You seem to be judging the likelihood of a slide based on a very small range of slope angle, which seems contrary to what I've read. Granted, I'm no expert. Are you really saying that I just don't have to worry if the angle slope is below 30?

 

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I've always heard "there are no avalanche experts."

 

 

 

That's a pretty dumb statement. There are trained professionals out there with 20-30 years or more of experience in avalanche prediction and control. They write textbooks on avalanche safety. They are responsible for maintaining avalanche safety on major ski hills and on mountain highways travelled by thousands of people per day. Not saying they are always right or infallible, but no one is - honestly though, what else are you going to call them but avalanche experts?

 

Wikipedia:

An "expert" is someone widely recognized as a reliable source of technique or skill whose faculty for judging or deciding rightly, justly, or wisely is accorded authority and status by their peers or the public in a specific well distinguished domain. An expert, more generally, is a person with extensive knowledge or ability in a particular area of study

 

 

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basing your avi assessment on angle of slope is crazy. There are tons of more variables than simply angle, especially in the PNW.

 

Not the NCs, but here's a good example of what you speak of:

http://www.pbase.com/nolock/image/106185823 - from Sept 28, on a (possibly) unnamed ridge N of the Lyell/Alexandra region in the CDN rockies...

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The magic 30dg number is what I learned in my basic avalanche course, i'm certified AIARE level 2 (American Institute for Avalanche Research and Eductaion). I do trust the 30 dg threshold for sure, although there are variables which can definetly make lower angle terrain dangerous - such as traveling in the runout zone of avalanche paths. Many days during the winter (particularly continental snowpack), you can be walking on flat terrain, and remote trigger an avalanche 1000s of feet away, if you are in the path, you could be a gonner. - Wet slabs can cut out at angles down to 25dgs - Also most avalanche fatalities occur in very small slides. You could be safe on a 28 dg face, then go over 33 dg roll for 10 feet that has a crevasse at teh bottom, and trigger the 10 foot zone and get carried into the terrain trap of the crevasse. I would reccomend to everyone buying an inclinometer and becoming familiar with using it.

 

Of course slab avalanches can occur on steep terrain, and of course it does not take a thick slab to knock you off your feet. 45dgs is prime slab avi terrain, although: past 55dgs slab avalanches are much less likely to occur, as that kind of terrain tends to sluff off new snow during and just after storms, but - sure slabs do form on truley steep terrain - esp with maretime snowpack. Of course there can be massive cornices and windslabs over very steep terrain as well. One always has to evaluate that kind of terrain for themselves.

 

There are many good books out there; I like the avalanche handbook.

 

The best you can do to stay safe is to educate yourself as best you can, pay attention to the NWAC, evaluate the conditions yourself, and then make your decsion while paying attention to protocal for traveling in avi terrrain. Often people who know that there is a weak layer or instability within the snowpack ski 30+ terrain anyway, they accept the risk.

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Early season snow on top of an old, sun-baked, snow pack, and a big avalanche the next day. Surprise?

 

Regardless, back on topic, fresh snow down to 3500' this morning, and it's raining at 300' as I type, so expect increasingly winteresque conditions and a poorly consolidated early season snow pack, IMLTPO.

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Thought y'all would like to see this pre-historic photo from 1st ascent of N Face of Colfax in '75; had the Chouinard straight points working this nice-looking ice. Pretty sure there was a Terrordactyl and a Coonyard ice hammer at play too. Didn't bother with screws (Warthogs and Coonyards) except at belays; ice was too crappy to waste time on pro.

 

Reilly

 

NFaceColfax_2Crop.jpg

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Thought y'all would like to see this pre-historic photo from 1st ascent of N Face of Colfax in '75; had the Chouinard straight points working this nice-looking ice. Pretty sure there was a Terrordactyl and a Coonyard ice hammer at play too. Didn't bother with screws (Warthogs and Coonyards) except at belays; ice was too crappy to waste time on pro.

 

Reilly

 

NFaceColfax_2Crop.jpg

 

Awesome.... thats pretty cool stuff. Is that one of the ice routes? Or that big seraced face to the left of those route?

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Redistributed storm snow from mod to strong outflow winds, and Mid Pack Facets are two things that we are monitoring at Highways North Cascades (Coquihalla) The snowpack is at 54cms at hwy pass (102 cm long term average) and at our High stations it currently reads 94.cms. The snow pack has a real continental feel these days! Cms X .3937 = inches for my american friends!

 

FYI chris link..

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As you look at the north side it goes just up the left side along side the rock. I think it was in Beckey but not well-described, not that it really is worth it. It was just something to do one mid-September day with someone who had never swung an ice-hammer before! "You wanna get hard or what?" After the after-dark down-climbing the rock in crampons with the flashlight in the mouth the answer was "No, I guess not."

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