In the 1960s, weather scientists found that the chaotic nature of Earth’s atmosphere would put a limit on how far into the future their forecasts might peer. Two weeks seemed to be the limit. Still, by the early 2000s, the great difficulty of the undertaking kept reliable forecasts restricted to about a week.
Now, a new artificial intelligence tool from DeepMind, a Google company in London that develops A.I. applications, has smashed through the old barriers and achieved what its makers call unmatched skill and speed in devising 15-day weather forecasts. They report in the journal Nature on Wednesday that their new model can, among other things, outperform the world’s best forecasts meant to track deadly storms and save lives.
“It’s a big deal,” said Kerry Emanuel, a professor emeritus of atmospheric science at the Massachusetts Institute of Technology who was not involved in the DeepMind research. “It’s an important step forward.”
In 2019, Dr. Emanuel and six other experts, writing in the Journal of the Atmospheric Sciences, argued that advancing the development of reliable forecasts to a length of 15 days from 10 days would have “enormous socioeconomic benefits” by helping the public avoid the worst effects of extreme weather.
Ilan Price, the new paper’s lead author and a senior research scientist at DeepMind, described the new A.I. agent, which the team calls GenCast, as much faster than traditional methods. “And it’s more accurate,” he added.
He and his colleagues found that GenCast ran circles around DeepMind’s previous A.I. weather program, which debuted in late 2023 with reliable 10-day forecasts. Rémi Lam, the lead scientist on that project and one of a dozen co-authors on the new paper, described the company’s weather team as having made surprisingly fast progress.
“I’m a little bit reluctant to say it, but it’s like we’ve made decades worth of improvements in one year,” he said in an interview. “We’re seeing really, really rapid progress.”
DeepMind tested its new A.I. program against the center’s Ensemble Prediction System — a service that 35 nations rely on to produce their own weather forecasts. The team compared how the 15-day forecasts of both systems performed in predicting a designated set of 1,320 global wind speeds, temperatures and other atmospheric features.
