Accurate precipitation nowcasting is vital for disaster mitigation, but deep learning methods face a key trade-off: regression models produce over-smoothed, spectrally decaying predictions that blur convective details and violate turbulence power laws; diffusion models generate realistic yet unanchored hallucinations lacking physical grounding. We propose Spectral-Decoupled Iterative Refinement (SDIR), a deterministic framework that reformulates nowcasting as progressive frequency-decoupled refinement. SDIR first extracts a stable low-frequency synoptic skeleton, then iteratively refines high-frequency textures under physical constraints, eliminating both blurring and hallucinations. It features a dual-path design: the Synoptic Frequency-Guided Former (SFG-Former) with Scale-Adaptive Transformers for global structure, and the Fourier Residual Refiner (FR-Refiner) with Scale-Conditioned Fourier Neural Operators for fine residuals. A Physically Consistent Power Spectral Density (PCPSD) loss with dynamic masking enforces a turbulence-consistent spectral distribution. Experiments on three benchmarks show SDIR significantly outperforms SOTA methods in spatial accuracy while achieving spectral fidelity competitive with diffusion-based methods, enabling reliable high-resolution operational nowcasting.
@inproceedings{zhou2026sdir,title={Learning to Refine: Spectral-Decoupled Iterative Refinement Framework for Precipitation Nowcasting},author={Zhou, Yunlong and Zhao, Chen and Peng, Danyang and Ji, Fanfan and Yuan, Xiao-Tong},booktitle={Proceedings of the 43rd International Conference on Machine Learning (ICML)},year={2026},}
@inproceedings{peng2026lophyda,title={LoPhyDA: Low-Rank Tensor and Physics Gradient Guided Diffusion for Atmospheric Data Assimilation},author={Peng, Danyang and Chen, Yang and Zhou, Yunlong and Yuan, Xiao-Tong},booktitle={Proceedings of the 43rd International Conference on Machine Learning (ICML)},year={2026},}
@article{zhou2026crft,title={More realistic and accurate precipitation nowcasting with Conditional Rectified Flow Transformers},author={Zhou, Yunlong and Zhao, Chen and Ji, Fanfan and Hang, Renlong and Liu, Qingshan and Yuan, Xiao-Tong},journal={Engineering Applications of Artificial Intelligence},volume={165},pages={113402},year={2026},doi={10.1016/j.engappai.2025.113402},}
@article{zhou2024stean,title={Spatiotemporal Enhanced Adversarial Network for Precipitation Nowcasting},author={Zhou, Yunlong and Hang, Renlong and Ji, Fanfan and Pan, Zefeng and Liu, Qingshan and Yuan, Xiao-Tong},journal={IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing},volume={17},pages={7608--7620},year={2024},doi={10.1109/JSTARS.2024.3381822},}
@article{pan2024dual,title={Deep Precipitation Nowcasting With Dual Regions Displacement Information and Global Spatiotemporal Representations Learning},author={Pan, Zefeng and Ji, Fanfan and Zhou, Yunlong and Hang, Renlong and Liu, Qingshan and Yuan, Xiao-Tong},journal={IEEE Geoscience and Remote Sensing Letters},volume={21},pages={1--5},year={2024},doi={10.1109/LGRS.2024.3384772}}