The Impact of High-Resolution Terrain Data in WRF Simulations of Hurricane Maria (2017)

The atmospheric processes involved in a tropical cyclone, which manifest as rainfall, wind, and pressure, are affected by topographical factors during and after landfall. Interactions with land are capable of changing the tropical cyclone’s structure, behavior, and impact on the landmass. However, one of today’s forecasting problems is that computer models cannot interpret many of the factors that influence surface weather over complex terrain, and they give a forecast that presents the expected behavior of a tropical cyclone moving over a smooth landmass. This research project investigates the impact of high-resolution terrain data in WRF simulations of Hurricane María, focusing on its path through Puerto Rico. Two WRF simulations are compared to see the impact of the model’s terrain resolution. One of the simulations uses a default terrain dataset that considers Puerto Rico as a smooth surface and the other uses a high-resolution terrain data set that accurately represents the island’s mountainous topography. Differences between the two simulations are highlighted with time series of atmospheric variables at specific locations, horizontal maps of wind, rain, and other variables, as well as wind and rain swaths. The results demonstrate the impact of high-resolution terrain data on WRF tropical cyclone simulations and show that the high-resolution topography produces more realistic results in terms of the hurricane’s structure and behavior. It is expected to concluded that high-resolution land data will lead to more accurate forecasts of wind and rain in cases when a tropical cyclone interacts with a landmass.