Evaluation of the National Water Model for Puerto Rico

Abstract

In Puerto Rico, a territory of the United States in the Caribbean, the past decades have been plagued with frequent floods, some of which (e.g. Hurricanes Irma and Maria in 2017) have been catastrophic. Puerto Rico’s enhanced hydrologic risk can be attributed to the topographic features and weather patterns of a tropical climate, including frequent high intensity convective rainfall and the seasonal risk of hurricanes and tropical storms. The NOAA’s National Water Model (NWM) became operational in August 2016, and serves as the first real-time distributed continuous hydrologic forecast system over the United States. It provides high-resolution and significantly-expanded forecast guidance coverage in underserved locations, but to date is only available over the continental United States. This study incorporates multiple forcing datasets (the Global Forecast System, the High Resolution Rapid Refresh Model, a 1-km WRF-CARICOOS forecast model, and a High-Resolution Retrospective Analysis Forcing Dataset) using a developmental Puerto Rico domain of the National Water Model to examine the impact of different forcing data resolution in the streamflow output. This will be a first step towards having a more complete distribution of hydrologic information and forecast guidance data throughout the island to better understand and anticipate flooding events.