Dynamic Downscaling of Coastal-Urban Caribbean Islands Extreme Weather Events Using High-Resolution Urban WRF

This study evaluates the performance of the Weather Research and Forecasting (WRF) model, enhanced with multi-layer urban canopy parameterizations (BEP-BEM), in capturing the unique microclimates of Caribbean coastal-urban environments. Leveraging Local Climate Zone (LCZ) mapping developed under the World Urban Database and Access Portal Tools (WUDAPT) framework, this study incorporates detailed representations of urban land cover and morphology. While LCZ methods have been widely applied to urban environments, this is among the first applications to tropical coastal cities in Puerto Rico and the United States Virgin Islands (USVI), highlighting their utility for small island settings. The simulations focus on the extreme summer heat experienced in the Caribbean during the summer of 2023, a period characterized by record-breaking temperatures and amplified urban heat stress. Using a nested domain setup at 9 km, 3 km, and 1 km resolutions (D01, D02, D03), the simulations are driven by ERA5 Reanalysis (~27 km resolution) to resolve key physical processes. The primary focus is to assess the ability of the urban WRF to capture coastal-urban boundary-layer dynamics, urban heat islands, and localized convection over small islands in the Caribbean. A key innovation of this study is the application of BEP-BEM schemes, which account for building energy exchanges and urban morphology, enabling a detailed representation of urban-atmosphere interactions. Preliminary results highlight the model's ability to capture fine-scale phenomena, including coastal breezes and urban-induced temperature gradients, critical for understanding the energy-air quality nexus and extreme weather behavior in these regions. This approach provides valuable insights into the fidelity of modeling tools for coastal-urban systems, particularly for small islands where urban footprints significantly influence atmospheric processes. By focusing on a specific extreme heat event, this study enhances understanding of coastal-urban interactions and informs climate resilience strategies for vulnerable regions.