Coastal environments, home to nearly 40% of global population, face unique hydroclimatological challenges including tropical cyclones, extreme precipitation, storm surges, and heat-humidity extremes. These risks are compounded in coastal cities by population growth, land use changes, and climate change. In particular, the presence and growth of cities in these regions adds a layer of complexity to their meteorology and hydroclimate, as urbanization alters land characteristics that modulate atmospheric circulations and thermodynamics in ways that are not completely understood.

Water isotope ratios offer a tested way to gain additional information about physical mechanisms in studies of the water cycle at global as well as regional scales. This work leverages such capabilities by using the water-isotope-enabled version of the Weather Research and Forecasting model, WRF-Hydro-iso (Arnault et al., 2021), to study the impacts of Houston, a major coastal urban area, on the local and regional hydroclimate. We perform simulations that probe the effects of different urban land surface properties on precipitation and mesoscale circulations. By integrating simulated data with observed water isotope ratios and other hydrometeorological variables from TROPOMI and the TRACER ARM campaign, we aim to track the mechanisms responsible for these changes.