Hey all, many of you are likely familiar with the 'yesterday's weather' anecdote from Extreme Programming, that goes something like this:

'Some country decides to build a sophisticated computer system to predict the weather. After spending more money than I can imagine, they come up with wonderful result - and proudly claim that the system is 70% accurate. Somebody then figures out that in this country if you predict today's weather will be the same as yesterday's weather you will be 69.5% accurate.' (Taken from Martin Fowler's blog)

It's often used in Agile as parable for estimating that you will do the same amount of work this iteration as you did in the last one.

I am curious: Is this story apocryphal? Real? Some mix of both? I am very curious about its origin and I'm having a hard time finding anything. Academic interest, not trying to undermine anyone's process ;)