The National Oceanic and Atmospheric Agency (NOAA) in the United States of America announced on 16 August 2016 that it had launched a new predictive model, the National Water Model. The Model will initially provide improved flash flood forecasts in headwater areas as well as water forecast information for many areas that are not currently covered.
The National Water Model runs on the NOAA’s new Cray XC40 supercomputer, using data from more than 8,000 US Geological Survey (USGS) gauges to simulate water levels for some 2,700,000 locations along the rivers and streams of the contiguous United States, and generating hourly forecasts for the entire river network. Previously, NOAA was only able to forecast streamflow for 4,000 locations every few hours.

Using the WRF-Hydro computer program developed by the National Council for Atmospheric Research (NCAR), the National Water Model utilizes advanced mathematical techniques to simulate conditions for points two miles (3.2km) apart on every significant river, stream, tributary and catchment.
The Model generates three predictions: an hourly high-resolution zero to 15 hour short-range forecast; a daily zero to 10-day medium-range forecast; and a zero to 30-day long-range water resource forecast.
GIS “smart mapping” firm Esri provided the graphic interface for the model, with “a robust collection of web maps” that display NOAA forecast streamflow data. According to Esri, although the mid-range 10-day forecasts contain more than 200 million records and short-term forecasts require hourly data refresh, their maps automatically integrate and synthesize NOAA data so that users have the real-time information they need. Esri has announced plans to release an open-source toolkit later in 2016 that will enable ArcGIS users to analyze data and create custom maps from water model records.
NOAA developed and implemented the model in association with NCAR, the Consortium of Universities for the Advancement of Hydrologic Sciences, the National Science Foundation, and federal Integrated Water Resources Science and Services Consortium partners. The development of this model follows the opening of the National Water Center at the University of Alabama in May 2015.
It is proposed to develop the model to provide ‘zoomed-in’ street-level forecasts and inundation maps to improve flood warnings, and also to provide predictions on snowpack conditions, lake and reservoir levels, subsurface flows, soil moisture and land-atmosphere interactions such as evapotranspiration.
“With a changing climate, we’re experiencing more prolonged droughts and a greater frequency of record-breaking floods across the country, underscoring the nation’s need for expanded water information,” said Louis Uccellini, Ph.D., director of the National Weather Service. “The National Water Model will improve resiliency to water extremes in American communities.”
