The forecast moved again

A family in Dubai plans a night camping in the mountains near Hatta.

On Monday the weekend looks clear. By Wednesday there is a chance of rain on Saturday. On Thursday the chance has slid to Sunday morning. Someone in the group chat declares the forecast useless, because it keeps changing.

But the changing is the whole point.

A forecast is a guess made with the best information available on the day it is made. When the information improves, the guess improves with it. A forecast that never moved would be the suspicious one, because it would mean nobody was looking.

What frustrates the family is not the weather. It is the wish for certainty, the hope that Monday's picture of Saturday was a promise rather than an opinion. Nobody signed anything. The clouds were never consulted.

The same wish follows us into every plan we make about other people. How many will come, how many will buy, how many will stay. We write the number down, the number starts to feel like a fact, and when it moves we treat the movement as a failure by whoever wrote it.

It is the opposite of a failure. The revision is the forecast being honest about what it is.

We keep asking guesses about the future to behave like records of the past, and we keep being disappointed when they decline. They were never records.

A number about the future that keeps moving is not broken. Every time it moves, it is telling you what kind of number it was all along.