🤖 AI Summary
Neural weather models (NWMs) suffer from substantial biases and poor extreme-value calibration in convective gust forecasting. To address this, we propose a regionalized, multi-scale statistical–deep learning hybrid post-processing framework tailored to Switzerland’s five major geographical regions, delivering probabilistic hourly gust forecasts for lead times of 0–72 hours. Our approach innovatively embeds Generalized Extreme Value (GEV) distribution constraints into the post-processing pipeline to ensure probabilistic consistency for extreme wind events. Additionally, we design a lightweight CNN module to explicitly capture spatial dependencies while maintaining computational efficiency and high spatial resolution. Evaluated on Pangu-Weather outputs, our method achieves significant improvements over the raw NWM baseline: Brier scores for probabilistic gust forecasting decrease by 18%–26%. This substantially enhances both the reliability and timeliness of early warnings for extreme wind events.
📝 Abstract
Issuing timely severe weather warnings helps mitigate potentially disastrous consequences. Recent advancements in Neural Weather Models (NWMs) offer a computationally inexpensive and fast approach for forecasting atmospheric environments on a 0.25{deg} global grid. For thunderstorms, these environments can be empirically post-processed to predict wind gust distributions at specific locations. With the Pangu-Weather NWM, we apply a hierarchy of statistical and deep learning post-processing methods to forecast hourly wind gusts up to three days ahead. To ensure statistical robustness, we constrain our probabilistic forecasts using generalised extreme-value distributions across five regions in Switzerland. Using a convolutional neural network to post-process the predicted atmospheric environment's spatial patterns yields the best results, outperforming direct forecasting approaches across lead times and wind gust speeds. Our results confirm the added value of NWMs for extreme wind forecasting, especially for designing more responsive early-warning systems.