What’s All the Fuss About...
Google GenCast
AI is about to make long-term weather forecasts much more accurate
What is it?
A new weather-forecasting system powered by AI that Google claims provides “more accurate forecasts up to 15 days ahead”. Created by DeepMind, Google’s AI laboratory, it’s better than many previous systems because it uses a diffusion AI model. But before we explain what that means, we need to talk about the difference between probabilistic and deterministic models to predict the weather.
OK, go ahead…
Historically, weather forecasts were largely deterministic, giving a single outcome based on numerical weather prediction (NWP) models. These models use complex equations to simulate atmospheric behaviour, but don’t take into account uncertainty. For example, they might forecast two inches of rain or 15°C temperatures without indicating how likely those outcomes are.