2006b). “Development, Calibration, and Implementation of a Distributed Hydrologic Model for Drainage Basins Located Along the Texas Gulf Coast for use in Real-Time River Flood Forecast Operations.” Coastal Hydrology and Processes. Edited by Vijay

The National Weather Service (NWS) West Gulf River Forecast Center (WGRFC) is currently developing, calibrating, and implementing distributed hydrologic models for use in real-time river forecast operations using the NWS Distributed Hydrologic Modeling System (HL-DHMS). Both the WGRFC and the Arkansas-Red Basin River Forecast Center (ABRFC) are serving as initial test sites for HL-DHMS. The models developed at the WGRFC and the ABRFC are the first distributed models to be implemented into real time river forecast operations within the NWS. Twenty-five headwater drainage basins across the state of Texas were selected for initial development using HL-DHMS. At the time this paper was submitted for publication, seventeen of these basins have been implemented into WGRFC operations, while eight are still under development. The watershed characteristics for each of these locations vary according to climatology, topography, vegetation type, soil type, land-use, and other hydrologic and hydrometeorologic factors. Drainage basins are defined on a nominal 4 km by 4 km grid network. Hourly gridded radar-based precipitation is forced into the system. From there, runoff production is computed for each grid cell using the distributed Sacramento Soil Moisture Accounting (SAC-SMA) method and is then routed to the basin outlet using the kinematic wave technique. The model parameters are calibrated utilizing historical precipitation estimates and streamflow data at the basin outlet. Upon successful calibration, each basin is incorporated into WGRFC river forecast operations. An overview of the issues regarding the development, calibration, and implementation of distributed hydrologic models using HL-DHMS for real time river forecast operations is presented