12/19: White Xmas probability

[Undertoad]

OK, these probabilities were determined yesterday, and this GIF image is too big and will take a while to load, but anyway...

For all the weather maps that we see, I don't recall ever having seen this particular one: probability of a white Xmas, a week out.

As time goes by, the ability of meteorologists to accurately predict this sort of thing will improve. They've probably been able to make a mpa like this, but to have it reflect any kind of reality - well, that's harder.

Semantically speaking, when forecasters mention "probability of precipitation", they are always wrong, aren't they? Because factored into that probability is the wiggle room that they may be wrong.

I can predict a 50% chance of rain tomorrow and be considered right, but the actual probability is fixed, unknowable by humans, and probably not 50%. And by the time it actually rains or doesn't, probability is no longer a factor. When something actually happens, the probability involved magically goes away.

One thing I find sad about weather maps is how everything just stops at the border. There's no Canada, no Mexico. These places still have probability. And in an increasingly globalized world (there's a redundancy for you!), it doesn't make sense to leave them off.