New National Water Model Upgrades Water Flow Forecasts
We could not live without the simple chemical compound H2O. Known as water in layman’s terms, it is a vital part of our bodies, our food, our lives, and our planet. But there are serious, catastrophic problems when water inundates communities as a flood event or disappears during drought conditions. These issues, in addition to increasing resource demand, create challenges for water managers. Water resource experts met this week at a University Corporation for Atmospheric Research (UCAR) congressional briefing, sponsored by Senator Richard Shelby (AL-7), to discuss the collaboration between government agencies, industry, and academia on the management and development of our nation’s vital water resources. This collaboration is no small feat – Mr. Edward Clark (Director, Geo-Intelligence Division, National Oceanic and Atmospheric Administration (NOAA)) told the audience there are 26 different federal agencies that work on water prediction, science, and data services.
Mr. Clark highlighted the National Water Model (NWM), a high-resolution tool that upgrades NOAA’s water flow forecasts. The NWM, launched in August 2016, is a hydrologic model that can simulate the water cycle and related river and stream forecasts. It will increase the areas that receive hydrological forecasts and improve the quality of data received. According to Mr. Clark, prior to the introduction of the NWM, almost one-third of the U.S. population (over 100 million people) lived in coastal areas that did not receive a hydrological forecast, and only 4,000 river locations were forecasted for streamflow. With NWM, 8,000 stream gauges will now provide forecast for 2.7 million stream locations. This expansion of locations for predictive water information is especially important due to the increasing socio-economic risks that droughts and flooding bring to U.S. communities.
The NWM will help prepare communities for extreme water events, such as flooding, and help industries improve water management decisions, such as those concerning irrigation or water conservation. Mr. John McHenry (Chief Scientist, Baron Advanced Meteorological Systems) noted that data the NWM will provide will be especially helpful in better predicting flood events. If the flood level can be determined beforehand, communities can relocate their assets prior to flooding, saving property, money, and perhaps even lives.
COL President Jon White, who has previously stressed the importance of forecasts and modeling, asked the panel if water resource agencies are also working on long-term probabilistic modelling of forecasts at the monthly, seasonal, and annual levels in addition to shorter-term deterministic forecasts. Deterministic forecasts provide a predicted occurrence based on a certain set of data and conditions, while probabilistic forecasts yield a distribution of all probable outcomes. Deterministic forecasts are usually used for the short term, and are considered to be what will happen, such as daily temperature forecasts. Probabilistic forecasts predict the probability of an event happening based on events in the past happening under similar conditions—which is what we hear on the news when there is a “60 percent chance of rain.” Dr. David Gochis (Scientist III, Research Applications Laboratory, Hydrometeorological Applications Program, NCAR) answered that probabilistic forecasts are indeed a focus for future development of the NWM and its associated weather service products.
Since the NWM was only launched last month, it is still in its early stages. Dr. Gochis explained that there is room for the model to evolve and expand to include water quality forecasts, which are especially important in monitoring harmful algal blooms off coastlines and eventually storm surge forecasts that will help protect U.S. coastlines. The NWM is an important piece of technology that simplifies complex water processes and will aid in accurate forecasting across the nation.