Eli5: Is weather *truly* predictable? Is it possible to develop a scientific model supported by satellites, software/ai, and super computers that could predict specific storms and events months/years/decades in advance?

Question

Elephant in the room: There are factors like volcanos and human involvement that create unpredictable variables

As above. And let me lead with this: I’m a smart guy, but i know little about meteorology. My question is grounded in ignorance.

Right now we can predict with relative accuracy storms and events 3-7 days out, depending on the scope of the storm. Temperatures are even ‘easier’.

It seems like we’re close (if not already there) to having global weather data at all times. We live in a world of scientific order, so shouldn’t we be able to create a model that very accurately predicts specific weather on a long timeline?

Exa: I’m ignorant in meteorology, but I would think all of the fronts and movements that will lead to a hurricane in the Atlantic in 2025 are already in motion. Couldn’t we track that *now*? Play out the equation, so to speak?

And then we’d be able to reverse engineer the moments that disrupted the model, to accurately determine what artificially affected the weather pattern.

Thanks! And sorry if I’m dumb.

In: Planetary Science

Answer 1

The weather, I am told, is (in the mathematical sense) a chaotic system. That means that even the tiniest error in the data we have, or the calculations we apply, can lead over time to a prediction far removed from what actually happens. Hold your next breath for 30 seconds, and the worldwide weather in a year or two may, quite literally, be totally different to what it would have been if you hadn’t. Or the famous phrase, the Butterfly Effect – a butterfly flaps its wings, and next year there’s a storm at the other side of the world that wouldn’t have otherwise happened.

Our actual data is massively incomplete; our computers only work to a given level of accuracy (significant digits, rounding and so on). We can refine that, and increase our accuracy – but, no, it’s never going to be perfect.

(Actual weather forecasting works on the basis of recognising that the data is imperfect. Run thousands of predictions, perturbing the data slightly each time, and see what trends dominate. Sometimes the system is pretty stable, many of the predictions are very similar, and you can say what’s likely to happen with a high degree of confidence. Other times, less so.)