Fusion of rain radar images and wind forecasts in a deep learning model applied to rain nowcasting
This research offers an incremental improvement in rain nowcasting accuracy, particularly for high precipitation events, which is beneficial for environmental applications like flood risk monitoring and agricultural management.
This paper addresses short- to mid-term rainfall forecasting by integrating rain radar images with wind velocity forecasts into a deep learning model. The proposed model achieved an 8% improvement in F1-score over optical flow for moderate and higher rain events at a 30-minute horizon, and a 7% improvement over a radar-only deep learning model.
Short- or mid-term rainfall forecasting is a major task with several environmental applications such as agricultural management or flood risk monitoring. Existing data-driven approaches, especially deep learning models, have shown significant skill at this task, using only rainfall radar images as inputs. In order to determine whether using other meteorological parameters such as wind would improve forecasts, we trained a deep learning model on a fusion of rainfall radar images and wind velocity produced by a weather forecast model. The network was compared to a similar architecture trained only on radar data, to a basic persistence model and to an approach based on optical flow. Our network outperforms by 8% the F1-score calculated for the optical flow on moderate and higher rain events for forecasts at a horizon time of 30 min. Furthermore, it outperforms by 7% the same architecture trained using only rainfall radar images. Merging rain and wind data has also proven to stabilize the training process and enabled significant improvement especially on the difficult-to-predict high precipitation rainfalls.