๐ค AI Summary
This work proposes the MP-MoE framework to address precipitation biases in numerical weather prediction (NWP) over tropical regions, where complex terrain and convective instability challenge forecast accuracy, and to mitigate the โdouble penaltyโ issue inherent in point-wise loss functions when temporal misalignment occurs. By introducing Matrix Profile into precipitation post-processing for the first time, the method constructs a subsequence-level, structure-aware loss function that guides a Mixture-of-Experts (MoE) model to dynamically select experts based on structural similarity. Evaluated on two major river basins in Vietnam, MP-MoE significantly outperforms both raw NWP outputs and existing baselines, achieving higher mean Critical Success Index (CSI-M) for heavy rainfall events and substantially reduced Dynamic Time Warping (DTW) distance, thereby better preserving storm morphology.
๐ Abstract
Precipitation forecasting remains a persistent challenge in tropical regions like Vietnam, where complex topography and convective instability often limit the accuracy of Numerical Weather Prediction (NWP) models. While data-driven post-processing is widely used to mitigate these biases, most existing frameworks rely on point-wise objective functions, which suffer from the ``double penalty'' effect under minor temporal misalignments. In this work, we propose the Matrix Profile-guided Mixture of Experts (MP-MoE), a framework that integrates conventional intensity loss with a structural-aware Matrix Profile objective. By leveraging subsequence-level similarity rather than point-wise errors, the proposed loss facilitates more reliable expert selection and mitigates excessive penalization caused by phase shifts. We evaluate MP-MoE on rainfall datasets from two major river basins in Vietnam across multiple horizons, including 1-hour intensity and accumulated rainfall over 12, 24, and 48 hours. Experimental results demonstrate that MP-MoE outperforms raw NWP and baseline learning methods in terms of Mean Critical Success Index (CSI-M) for heavy rainfall events, while significantly reducing Dynamic Time Warping (DTW) values. These findings highlight the framework's efficacy in capturing peak rainfall intensities and preserving the morphological integrity of storm events.