High-resolution modeling of typhoons over Osaka using Doppler lidar observations

Typhoons frequently cause significant damage over the highly urbanized coastal region of Osaka, Japan. Therefore, accurate high-resolution forecasts are crucial for mitigating the impacts of these extreme weather events. However, conventional numerical weather prediction systems often struggle to represent fine-scale atmospheric structures associated with typhoon intensity, wind distribution, and landfall timing. In this study, a high-resolution typhoon forecasting system was developed by integrating ground-based Doppler lidar wind measurements to improve the simulation of typhoons affecting the Osaka region. The Weather Research and Forecasting (WRF) model was configured at very high horizontal resolution (on the order of a few hundred meters) to better resolve local atmospheric processes and complex land–sea interactions. Multilayer wind measurements obtained from a Doppler lidar deployed in Osaka were assimilated into the model using observation nudging approach. We studied two destructive typhoons, Typhoon Lan (2023) and Typhoon Shanshan (2024), both of which produced severe wind damage across western Japan. Initial and boundary conditions were provided by GSM reanalysis and GFS forecast datasets, and simulations were initialized at multiple lead times to assess forecast robustness. Model performance was evaluated using surface observations from the Automated Meteorological Data Acquisition System (AMeDAS) and best-track data from the Regional Specialized Meteorological Center (RSMC). Results indicate that the inclusion of Doppler lidar observations substantially improved the representation of near-surface and boundary-layer wind fields, leading to more accurate typhoon tracks, landfall locations, and timing, particularly in areas close to the observation site. These findings demonstrate the value of integrating localized Doppler lidar observations into high-resolution numerical models for improving forecasts of typhoons and support the development of Doppler lidar based forecasting systems to enhance urban disaster preparedness and risk reduction.