Avalanche Discussion

Forgive me if this seems like a digression, but looking at this article about the recent financial catastrophes, I find it interesting that this sounds exactly like snow science:

www.nytimes.com/2009/01/04/magazine/04risk-t.html

Here's a quote from page four:

What will cause you to lose billions instead of millions? Something rare, something you’ve never considered a possibility. Taleb calls these events “fat tails” or “black swans,” and he is convinced that they take place far more frequently than most human beings are willing to contemplate. Groz has his own way of illustrating the problem: he showed me a slide he made of a curve with the letters “T.B.D.” at the extreme ends of the curve. I thought the letters stood for “To Be Determined,” but that wasn’t what Groz meant. “T.B.D. stands for ‘There Be Dragons,’ ” he told me.

There be dragons!

As grad student I attended a seminar where the speaker argued that the climate sensitivity was log-normally distributed.  Loosely speaking this means it has a longer, fatter tail at the high end of the range then a normal distribution.  Thus while the expected sensitivity might still be relatively small (e.g. a few degrees C), there exists a significant chance the outcome will be much worse.  Years later, it's still the thing that worries me most about climate change.

In the mid 1980's a few traders realized that the actual daily changes in foreign currency exchange rates had a fatter tail then the commonly assumed log-normal distribution.  They made a lot of money.

I have no idea whether the tail is fat or skinny on any of the relevant snow science distributions or even what they look like.  I think this type of argument is most relevant to persistent instabilities where there is a low probability of triggering something, but grave consequences if it is.  Other then our propensity to fall into heuristic traps, these tail events are the most worrysome to me because they are the most unpredictable for experienced, avi savvy skiers.

Too bad you can't apply the principles of triangular arbitrage to evaluation of instability.

Yeah, especially the idea that in theory triangular arbitrage is supposed to be risk free. I could go for some risk free bc!

Today's quote from NWAC doesn't lead me to think of the word "risk-free":

...extreme danger does not adequately emphasize the extent of the anticipated avalanche potential.

NWAC forecast

I was thinking more in terms of lemons and expert halos. Now we're in a more classical northwest cleansing period and the risks are rather obvious.