GenCast, an AI-powered weather prediction tool, can crank out 15 days of highly accurate weather forecasts in minutes. Not only will it help you dress right in the morning, but it can give valuable, life-saving warnings for extreme weather events.
How many times have you checked the weather forecast then left the house prepared for a sunny day only to be ambushed by an afternoon storm? Or worn your heavy coat to find that the temperature climbs too high to keep it on? The fact is, even though modern meteorology has come a long way, the sheer complexity of using hundreds of data points to predict the weather makes accurate forecasts hard to come by – especially the further out in time you go.
A new system recently announced by Google DeepMind called GenCast is set to make things a lot better.
The AI-powered program was trained on four decades of historical data through 2018, taken from the European Centre for Medium-Range Weather Forecasts’ (ECMWF) historical archives. The ECMWF is considered the most accurate weather-prediction service in the world. Archival data from the service including wind speed, temperature, and pressure at different altitudes all went into the training program.
Once the AI model was trained up, it was then asked to predict the weather for 15-day periods in 2019. When compared to the actual weather that occurred in that year, GenCast was 97.2% more accurate than the ECMWF predictions. When the window of the prediction time was narrowed to just 36 hours, GenCast did even better – it was 99.8% more accurate than ECMWF. Both metrics best Google's previous weather prediction program, known as GraphCast.
The new system works by generating 50 or more predictions of what the weather might look like based on current weather trends and then aggregates the information to make its forecast. According to Google, the system can generate its 15-day forecast in just eight minutes using one of the company's TPU v5 AI processors, as opposed to the hours it takes supercomputers to do the same.
"GenCast is a diffusion model, the type of generative AI model that underpins the recent, rapid advances in image, video and music generation," says Google on its DeepMind blog. "However, GenCast differs from these, in that it’s adapted to the spherical geometry of the Earth, and learns to accurately generate the complex probability distribution of future weather scenarios when given the most recent state of the weather as input."
In addition to helping you dress right for the day's weather, Google says GenCast will also be able to save lives by helping predict the path of severe weather events – an increasing occurrence due to accelerating climate warming – days before they strike. The company says the data GenCast produces could also help renewable energy efforts by, for example, detecting wind patterns for optimal placement and usage of wind farms.
While you can't currently download an app using GenCast, Google is making the data gleaned from testing as well as real-time forecasts available publicly and is encouraging researchers, meteorologists and other entities to take advantage of the technology, so don't be surprised if your current weather app starts become more accurate in the coming months.
The research behind GenCast has been published in the journal Nature.
Source: Scimex, Google DeepMind
AI should be able to predict weather better, but I'd like to know the actual accuracy, rather than an undefined "increase".
The second most important factor is area size. Predicting rainfall amounts in a specific square km in my area is pretty much impossible, since I might experience heavy rains while a km away is dry. If you make the area large enough, and the forecast vague enough (mix of sun and cloud), then you're pretty much able to claim accuracy, since somewhere will have cloud and somewhere will have sunshine at some time in the day. A temperature of 20C might be accurate averaged over a 200x200 km area, but some sites might be 5C and some 35C, so the forecast doesn't help decide how to dress for the day.
So, is this AI more accurate for every local weather forecast, meaning more accurate on how to dress for the day?
It is said that the Mexican weather girl is so renowned for her meteorology that people who don't even speak Spanish watch her reports.