The National Weather Service Implements New Science into Operational Forecasts

Increased demands for our Nation's finite water supply call for an expanded use of coupled National Weather Service (NWS) climate, weather and hydrologic analyses and information. To meet this need, the NWS is building upon National Oceanic and Atmospheric Administration (NOAA) investments in remote sensing; data automation; and advanced weather, climate and hydroscience modeling. The NWS Advanced Hydrologic Prediction Service (AHPS) meets this objective. AHPS applies new science to provide more accurate forecast information depicting the magnitude and certainty of occurrence for hydrologic events, ranging from droughts to floods. AHPS information can be posted on the internet, including flood-forecast maps. New model calibration strategies, distributed modeling approaches, ensemble forecasting and data assimilation techniques, enhanced data analysis procedures, flood-forecast inundation maps, advanced hydraulic routing models, and improved precipitation estimation techniques will be introduced. This paper describes these techniques, the new forecasting services and their implementation status.