The percentage, by the way, refers to the percent of days that experience precipitation when the expected weather conditions are in place.
Well hell, if I’d’ve known that, a whole lot of other things would’ve made sense years ago. Like how we can be in 80% chance of snow when it’s snowing on me.
At least I’m not alone.
Wow, I am right there with you on that one. I just kind of thought of it like Spock predicting odds for things based on sensor readings. I don’t see where people would get the idea that it referred to the amount of area that would get precipitation or the amount of time that would be spent precipitating, though. I wonder what meterologists do if there were conditions no one has ever seen before. Like if the sun exploded, you wouldn’t have any previous data to base a percentage on. On which to base a percentage.
Darn it: “…if there ARE conditions…”
I’m with jzimbert – I thought it was a prediction, like odds on a sports game.
I wonder how much it would cost to check the distribution of possible outcomes – say, by a Monte Carlo analysis – and weight the probabilities in the forecast accordingly. (Thus, if two equally likely tracks lead to 50%-rain conditions and 10%-rain conditions, report a 30% chance of rain.)
I don’t know if they do that… I get the impression from reading forecast discussions that they generally know which models are currently running the more accurate predictions, and they go with those with some modification for outliers.