FengWu: Pushing the Skillful Global Medium-range Weather Forecast beyond 10 Days Lead

TL;DR

FengWu is a novel AI-based global medium-range weather forecast system that leverages multi-modal deep learning and achieves accurate predictions beyond 10 days, outperforming existing methods in both skill and efficiency.

Contribution

The paper introduces FengWu, a new AI-driven weather forecasting model with a multi-modal, multi-task architecture, and a replay buffer, extending skillful predictions beyond 10 days.

Findings

FengWu outperforms GraphCast in predicting 80% of key variables.

Reduces RMSE of 10-day global z500 prediction from 733 to 651.

Achieves forecast skill extension to 10.75 days lead time.

Abstract

We present FengWu, an advanced data-driven global medium-range weather forecast system based on Artificial Intelligence (AI). Different from existing data-driven weather forecast methods, FengWu solves the medium-range forecast problem from a multi-modal and multi-task perspective. Specifically, a deep learning architecture equipped with model-specific encoder-decoders and cross-modal fusion Transformer is elaborately designed, which is learned under the supervision of an uncertainty loss to balance the optimization of different predictors in a region-adaptive manner. Besides this, a replay buffer mechanism is introduced to improve medium-range forecast performance. With 39-year data training based on the ERA5 reanalysis, FengWu is able to accurately reproduce the atmospheric dynamics and predict the future land and atmosphere states at 37 vertical levels on a 0.25{\deg} latitude-longitude resolution. Hindcasts of 6-hourly weather in 2018 based on ERA5 demonstrate that FengWu performs better than GraphCast in predicting 80\% of the 880 reported predictands, e.g., reducing the root mean square error (RMSE) of 10-day lead global z500 prediction from 733 to 651 $m^{2}/s^2$. In addition, the inference cost of each iteration is merely 600ms on NVIDIA Tesla A100 hardware. The results suggest that FengWu can significantly improve the forecast skill and extend the skillful global medium-range weather forecast out to 10.75 days lead (with ACC of z500 > 0.6) for the first time.