Generalizing Weather Forecast to Fine-grained Temporal Scales via Physics-AI Hybrid Modeling
Wanghan Xu, Fenghua Ling, Wenlong Zhang, Tao Han, Hao Chen, Wanli Ouyang, Lei Bai
TL;DR
The paper tackles the limitation of black-box ML weather forecasts in generalizing to finer temporal scales. It introduces WeatherGFT, a physics-AI hybrid that uses a PDE kernel to drive short-time physical evolution and a learnable router to adaptively correct AI-based residuals, with a lead-time conditional decoder and multi-lead-time training to enable forecasts at finer horizons than the training data. The approach demonstrates that WeatherGFT can generalize to 30-minute forecasts from hourly data and provides competitive performance on medium-range tasks, while also delivering improved nowcasting results using 30-minute ground truth for validation. The work offers a principled pathway to bridge nowcasting and mid-range forecasting, with interpretable physics-driven evolution and adaptive AI corrections that enhance generalization and robustness.
Abstract
Data-driven artificial intelligence (AI) models have made significant advancements in weather forecasting, particularly in medium-range and nowcasting. However, most data-driven weather forecasting models are black-box systems that focus on learning data mapping rather than fine-grained physical evolution in the time dimension. Consequently, the limitations in the temporal scale of datasets prevent these models from forecasting at finer time scales. This paper proposes a physics-AI hybrid model (i.e., WeatherGFT) which generalizes weather forecasts to finer-grained temporal scales beyond training dataset. Specifically, we employ a carefully designed PDE kernel to simulate physical evolution on a small time scale (e.g., 300 seconds) and use a parallel neural networks with a learnable router for bias correction. Furthermore, we introduce a lead time-aware training framework to promote the generalization of the model at different lead times. The weight analysis of physics-AI modules indicates that physics conducts major evolution while AI performs corrections adaptively. Extensive experiments show that WeatherGFT trained on an hourly dataset, effectively generalizes forecasts across multiple time scales, including 30-minute, which is even smaller than the dataset's temporal resolution.
