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GraphCast: AI model for weather forecasting

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Re: GraphCast: AI model for weather forecasting

#281

The multimesh is interesting. Still, I bet the Fourier Neural Operator approach will prove superior. Members of the same team (Sanchez-Gonzales, Battaglia) have already published multiple variations of this model, applied to other physical scenarios and lots of them proved to be dead ends. My money is on the FNO approach, anyway, which for some reason is only given a brief reference. To their credit DeepMind usually…

How is that a disclosure?

Re: GraphCast: AI model for weather forecasting

#282

Similar methodologies are being applied to climate modeling, too. The Allen Institute has worked on it for a while, and has hired quite a few PhDs ( https://allenai.org/climate-modeling ).

why is hiring phds a measure?

in this particular case, most of the important/needle-moving work being done in climate modeling is done with a hell of a lot of context about prior work. PhDs have that, by necessity.

They're also good at prioritizing outcomes, rather than other stuff.

Re: GraphCast: AI model for weather forecasting

#283

I find this quite surprising actually. You'd think predicting the weather is mostly a matter of fast computation. The physical rules are well understood, so to get a better estimate use a finer mesh in your finite element computation and use a smaller time scale in estimating your differential equations. Neural networks are notoriously bad at exact approximation. I mean you can never beat a calculator when the issue…

AI/ML's bitter lesson [1] applies again. In this case, the AI model may have learned a more practical model than the one human researchers painstakingly came up with by applying piles and piles of physics research. [1] http://www.incompleteideas.net/IncIdeas/BitterLesson.html

> by applying piles and piles of physics research.

You mean by remembering piles and piles of example data and interpolating between it.

Re: GraphCast: AI model for weather forecasting

#284
post #250

I've been really impressed at how much better weather forecasting has become already. I remember weather forecasts feeling like a total crapshoot as recently as 15 years ago or so.

Isn't that highly subjective to where you live? Because I moved to Scandinavia and the forecast here is so incredibly bad, compared to central europe.

The accuracy is definitely location dependent, but I anecdotally agree with the GP that the accuracy has improved substantially, at least for the UK where I am.

Ten years ago, the weather forecast was so unreliable that I just assumed anything could happen on a given day, no matter the season. Frequently it would be unable to even tell you whether it was currently raining, and my heuristic for next day forecast instead was to just assume the weather would be the same as today.

Nowadays I find the next day forecasts are nearly always accurate and hourly precipitation forecasts are good enough that I can plan my cycles and walks around them.

Re: GraphCast: AI model for weather forecasting

#285

I find this quite surprising actually. You'd think predicting the weather is mostly a matter of fast computation. The physical rules are well understood, so to get a better estimate use a finer mesh in your finite element computation and use a smaller time scale in estimating your differential equations. Neural networks are notoriously bad at exact approximation. I mean you can never beat a calculator when the issue…

It's more like table lookup or interpolation than actual computation.

Re: GraphCast: AI model for weather forecasting

#286

Earlier quoted context omitted.

You assuming OpenAI's models are AGI tells more about you than anything else.

If Alan Turing says ChatGPT is an AGI, it's good enough for me.

I doubt he would've, half the point of Turing's paper was to stop people from debating what is or isn't "thinking" and to focus on the actual capabilities instead (like passing the test). He specifically wrote:

> "Can machines think?" I believe to be too meaningless to deserve discussion.

So I don't think he would've appreciated such a fuzzy concept as AGI.

Re: GraphCast: AI model for weather forecasting

#287

I find this quite surprising actually. You'd think predicting the weather is mostly a matter of fast computation. The physical rules are well understood, so to get a better estimate use a finer mesh in your finite element computation and use a smaller time scale in estimating your differential equations. Neural networks are notoriously bad at exact approximation. I mean you can never beat a calculator when the issue…

Shortcuts 100% exist. Imagine another physical problem. Simulating a sand grain and how it bounces off other sand grains or lodges against them. If you wanted to simulate a sand mountain, you could use a massive amount of compute and predict the location and behaviour of every single grain. Or, you could take a bunch of well-known shortcuts and just know that sand sits in a heap at the angle-of-repose. That angle dec…

The point was that weather, unlike a sandheap, is a chaotic hydrodynamic system with turbulent flows, that means it's computationally intractable to do exactly, which is why weather forecasts are only good for a few days anyway.

The example you gave does not really explain anything.

Re: GraphCast: AI model for weather forecasting

#288

The multimesh is interesting. Still, I bet the Fourier Neural Operator approach will prove superior. Members of the same team (Sanchez-Gonzales, Battaglia) have already published multiple variations of this model, applied to other physical scenarios and lots of them proved to be dead ends. My money is on the FNO approach, anyway, which for some reason is only given a brief reference. To their credit DeepMind usually…

Pragmatically speaking, it doesn't really matter if one is better than the other, at least until there is a massive jump in forecast quality (e.g. advancing the Day 5 accuracy up to Day 3). In the real world, we would never take raw model guidance from _any_ source - the best forecasts invariably come from consensus systems that look across many different models. So it's good to have a diverse lineage of forecasting systems, as uncorrelated errors boost the performance of these consensus systems.

Re: GraphCast: AI model for weather forecasting

#289

Yandex claims to be using AI-based weather forecasting for a good part of a decade and claims it as a success. It is quite good. https://meteum.ai/

My understanding is that they just use an AI-based precipitation nowcast (see [1]). Very different forecast/modeling problem than GraphCast.

[1]: https://arxiv.org/abs/1905.09932

Re: GraphCast: AI model for weather forecasting

#290

Earlier quoted context omitted.

IIRC the MetNet announcement a few weeks ago said that their model is now used when you literally Google your local weather. I don't think it's available yet to any API that third party weather apps pull from, so you'll have to keep searching "weather in Seattle" to see it.

Any idea why it is still showing the "weather.com" link next to the forecast?

Most likely explanation would be that Weather.com signed a contract with Google X years ago to have something placed there, and nobody wants to do the work to do anything about it.
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