0% Chance?

About 8 days before the NYC Marathon, I checked the long range weather report. Pure folly, I know, but what it said caught my attention.

It said that there was a 0% chance of precipitation. Zero percent? Really. Do they know what that means? Is this like Wallace Shawn's "inconceivable!" in The Princess Bride? I'm with Inigo Montoya -- "You keep using that word. I do not think it means what you think it means."

In my book, saying that there is a 0% percent chance means that it's just not going to happen. Yet three days later, there was a 40% chance of precipitation on marathon day. Huh.

To be fair, we all know that today's meteorologists would never claim that they could predict such a thing with certainty from 8 days out. So what DO they mean?

Here's my theory. Let's say you look out the window today, and it's cloudy. Is it going to rain? Maybe. Let's say there's a 40% chance, judging from the darkness of the clouds. Or, let's say the sky is blue -- no clouds in sight. Is going to rain? No way. Meteorologists have more to go on than what they see out the window, but they do the same thing. So, when they say 0% in 8 days, they mean they think it's going to be a clear day. 0% is not the chance that they are wrong. That, they do not publicize. 0% is just the chance that it will rain if they are right.

At any rate, the good news is that after a few days predicting rain, the forecast has returned to perfect. With the start 24 hours away, I'm feeling a little better about this claim of 0%.

Sun
Nov 1

Partly Cloudy

56°
45°

0%