Application of NEXRAD for Freshwater Inflow Estimates to Texas Bays and Estuaries

National Weather Service (NWS) rain gauge data has been applied in rainfall-runoff models to estimate inflows to Texas' bays and estuaries for decades by the Texas Water Development Board (TWDB). In an effort to improve the spatial and temporal resolution of rainfall data, TWDB recently launched a pilot project to study the applicability of NEXRAD data for this purpose. Rainfall along the Texas coast is highly variable both spatially and temporally, especially during summer time, making NEXRAD data advantageous over the rather sparsely distributed rain gauge network. Comparisons of rainfall and of modeled runoff using NEXRAD and NWS raingage data are presented at the basin and watershed scale. Advantages and issues with the conversion to use of NEXRAD are presented. Future study will focus on use of distributed rainfall/runoff models to take advantage of the readily available digital data.