Learning joint probabilistic weather forecasts from station observations alone
This study addresses the challenge of generating joint probabilistic weather forecasts with inter-variable dependencies using only station observations to assess compound meteorological risks. To this end, we propose CLARA, a lightweight, CPU-friendly architecture comprising approximately 28,000 parameters. By leveraging a calibrated advection-routing attention mechanism, CLARA directly learns joint Gaussian predictive distributions for five surface variables from station data without requiring numerical weather predictions or reanalysis products. Furthermore, we develop a consistent covariance scale estimator and demonstrate that neglecting inter-variable correlations significantly degrades negative log-likelihood performance. Experiments across ten global regions reveal that CLARA reduces energy scores by 4.9%–65% relative to baselines, outperforming the persistence baseline in all 60 comparisons and a comparable-scale model in 57 instances.