How to evaluate for avalanche, in spring, winter?

[DanO]

I am not new to climbing, but new to spring and winter

accents in the cascades as a leader.

 

I have looked at whitehorse to climb sometime in the future,

maybe this end of winter and spring. I looked at the standard

route and the glacier route.

 

 

I checked the general avalanche forecast for the region and

it looks pretty good as far as I know, a 1 for less than

5000 feet and a 2 for above 5000 feet.

 

I not planning to do the climb this weekend as I am tied up

Sunday, but would you consider it a green light as far as

general avalanche danger and weather conditions?

 

What else should I consider? I know about snow loading

in general but not sure how to apply this exactly on this

climb.

 

Is there a check list procedure?

 

Thanks

 

Dan

Edited February 19, 2010 by DanO

[selkirk]

I think with Avalanche danger it's always a check and verify process. The NWAC website is a great starting place and is probably good for a go / no-go decision in Seattle.

 

Once you're there though you should absolutely be checking snow conditions and digging a couple of pits on representative slopes / exposures to be sure.

 

IMHO the only defense against avalanche is information and a willingness to go home and drink beer.

[gyro]

I dunno, I'm sort of biased I guess, but if it was me I'd invest in a avalanche course. I've gone through AIARE classes and enjoyed the experience and learned a lot.

 

The thing is, you can't really just look at the avalanche rating and say yes or no. You need to be able to understand what the aspect is that was given what rating, what about that aspect that creates the chance for instability, and then have the tools to verify it for yourself in the field. The best way to be able to do that is actual practice, and a good place to start is a class.

 

I know there are several organizations that provide checklists, including AIARE. The checklist isn't much good though without the other skills. Here is what I do for a trip though.

 

I print out the avalanche report for the region, if one is available, sometimes climbs I do don't have any reports. I highlight the relevant portions. Slope facing what direction, windward or leeward, precipitation, etc... I find exactly what aspects are rated what.

 

Then I look at my climb, and my routes. Routes, plural is important. Plan more than one, and make sure one route is to the nearest bar. Like selkirk said, if your not willing to turn around and go home, you're in trouble.

 

I look at my routes, and I see which ones take me through what avalanche terrain (get a map inclinometer to help determine slope). I see what aspects on the route in avalanche terrain match up to aspects listed in the avalanche report. Wherever there is overlap is where I focus on avoiding if possible.

 

Once I am there, and I know the aspects I'm going to be on and concerned about from the report, I dig some snow pits, record my observations, give my own rating to the snow layers looking for strong over weak, etc... All the while looking to confirm what I saw in the avalanche report, the specifics, old facets, etc...

 

Once I've examined the layers I do some column tests, see where it fails, see if my results line up with the report.

 

The one thing that always is good to remember is that you can never downgrade avalanche danger from your observations, you can only upgrade it. Also, are you with a group that knows how to rescue a buried victim? These are important things to ask yourself to make sure that your decision to go or not is an informed one.

 

Keep in mind, the avalanche report now could be very different in two weeks or whenever you go.

[cbcbd]

If you're looking for a checklist, the best one I've seen is the one on pg 5 of the AIARE field book. Gyro hit most of the things included in that list and I think he's right - "The checklist isn't much good though without the other skills."

 

AIARE Avy 1 is a great course that should really help you make better decisions and just help you know what to look for - lostsa fun.

[Jamie]

Seaberry Blair said it nicely one time. He said he finds lots of places to go where the avalanche hazard just doesn't exist. I know that is not always possible if you want a summit, but there is some logic to his reasoning. Did you know that most people killed in avalanches have been through some sort of training (and I know correlation doesn't necessarily show cause)? Recently some mathematical models of sand avalanches has shown there are enough factors that predicting the event proves impossible.

( see "Ubiquity" by Mark Buchanan). There are lots of "rules of thumb" for avalanches, but the last rule of thumb is that their are no reliable rules of thumb. They can happen when not expected and under conditions not normally associated with high avalanche hazard. And one more psychological note. The more you travel in those conditions the more callus you get and the less you will respect the danger. Avalanches don't happen often enough for you to psychologically associate that big snow load with the hazard. Sorry for the rambling, I know I talk too much.

Edited February 23, 2010 by Jamie

[gyro]

With all due respect, taking an AIARE course is not the same as reading up on "rules of thumb" and equating all of the knowledge available about avalanches and best practices to some sort of collection of old wives tales is disingenuous. The lowest degree slope that an avalanche is known to have occurred on is 11 degrees, so the advice to always stay away from places where avalanches could happen just isn't realistic. Definitely be willing to turn back, but the overall gist of your post that I got is "don't try to learn, it is just too complex" which I think is a horrible message to send. There is much that can be learned to mitigate risks. It won't confer a magical ability to predict avalanches, but it will help you make better choices.

[Jamie]

okay, I agree. And after all, we are climbers so we assume some degree of risk.

[YocumRidge]

What else should I consider? I know about snow loading

in general but not sure how to apply this exactly on this

climb.

I second the suggestion of others - do yourself a favor and take an AIARE Avy Level I course. If you are into downhill B/C skiing and ski mountaineering, follow up with the Level II as well. Level I is invaluable if you want to try out different types of beacons/rescue scenarios and see what works best for you plus get skills on safe routefinding in the avy-prone terrain and WHERE to dig snow pits so the accidents like that would not happen: http://www.dailyastorian.com/Main.asp?SectionID=2&ArticleID=59014

 

And "as a leader" make sure that members in your team dont just carry beacons but actually know how to use them both in receiving and transmitting modes.

 

Is there a check list procedure?

Checklist on p5 of the AIARE field book is good but I prefer

Life-Link Avy Snow Pit/Rutschblock card and Life-Link Backcountry travel in Avy terrain card.

Both are 5" x 3", laminated and stuffable in your pocket, user friendly cheat sheets. The snow pit card has everything you need to know how to dig and analyze pits for shear quality, compression test and shovel shear plus the rutschblock. It does not have ECT and lemons though which you might want to photocopy and add extra.

 

"Staying Alive in Avalanche terrain" by Bruce Tremper, II edition is outstanding reading for Avy safety.

 

[Joe_Poulton]

Bruce Tremper's book is awesome...thick and packed full of great info. I've read it 3 times through now and each time I remember more and more of the tidbits that help. Great read!

 

 

[johndavidjr]

I know more than nothing but much less than a lot about this, & was acquainted with at least a couple of very, very experienced people who guessed all wrong.

 

I wonder though, if you printed out the forecast, dug multiple pits, did multiple block tests & etc., whether you'd actually get to climb anything by the time you're done& & whether or not these procedures tell you what's happening 2,000 feet upslope from whence things might land upon y'all.

 

Perhaps having adequate experience/snow sense/luck could make up for these various steps.

 

The whole topic scares me.

[gyro]

I wonder though, if you printed out the forecast, dug multiple pits, did multiple block tests & etc., whether you'd actually get to climb anything by the time you're done& & whether or not these procedures tell you what's happening 2,000 feet upslope from whence things might land upon y'all.

 

Well, you get the forecast before you leave so that doesn't cut into climbing time. You only need one pit for each aspect you are concerned about, and depending on the forecast and your findings, you don't need to dig the full meter deep pits every time. There are a number of methods to make quick upper snow pack observations without digging a massive hole. For digging the full pits though, it shouldn't take more than 15 minutes or so of digging and smoothing before you can make some observations and do some tests, so about a half an hour. Also, you would do your tests in the same aspect, and that would ideally include elevation, so when you got to the elevation you are concerned about, then you would do some additional tests.

 

Perhaps having adequate experience/snow sense/luck could make up for these various steps.

 

Nope.