When it rains, it pours: the National Oceanic and Atmospheric Administration has announced another major upgrade to the U.S.’ Global Forecast System (GFS). The new upgrade to the model, which serves weather forecasting across the country, will improve its overall resolution, along with its ability to forecast hurricanes, snowfall, rainfall and more.
The new upgrades collectively iterate the GFS to v16, including new coupling with a global wave model (WaveWatchIII). Compared to its predecessor, GFSv16 is better able to predict the formation of hurricanes, identify where snowfall will land and forecast heavy rainfall (thanks to general atmospheric physics improvements), as well as anticipate ocean waves up to 16 days in advance (thanks, of course, to the WaveWatchIII integration). GFSv16 also has nearly double the vertical resolution of the previous iteration, with 127 vertical levels (compared to 64 previously). These improvements were verified through a retrospective, comparative analysis of the 2018 hurricane season and the period from May 2019 to present.
GFSv16 comes on the heels of a series of major announcements in the U.S. weather forecasting space over the last two years. In June 2019, the GFS was given its first new dynamical core in nearly 40 years – the Finite-Volume Cubed-Sphere (FV3) dynamical core – which dramatically improved the GFS’ ability to predict winter storms and tropical cyclones and generally improved 1-2 and 3-7 day forecasting abilities.
Then, in February 2020, NOAA announced plans to triple the U.S.’ weather and climate supercomputing capacity through two new Cray Shasta systems, each with a peak performance of 12 petaflops (bringing the agency’s targeted aggregate capacity to 40 peak petaflops). And, most recently, in September 2020, NOAA announced that it was implementing the FV3 into its ensemble forecast model, improving its spatial resolution and extending its overall range to 35 days. This new upgrade, meanwhile, is the first upgrade to the primary GFS since that FV3 upgrade in June 2019.
“This substantial upgrade to the GFS, along with ongoing upgrades to our supercomputing capacity, demonstrates our commitment to advancing weather forecasting to fulfill our mission of protecting life and property,” said Louis W. Uccellini, director of NOAA’s National Weather Service. “Today’s upgrade also establishes a strong foundation for further planned enhancements that will allow for the assimilation of even more data into the model.”
All of these efforts fall under NOAA’s long-term goal of developing its “Next-Generation Global Prediction System” (NGGPS), an umbrella initiative for the series of ambitious upgrades. “[The NGGPS] is an ongoing effort to leverage the expertise of the broader weather community and expedite the research to operations pathway,” explained Vijay Tallapragda, chief of the Modeling and Data Assimilation Branch at NOAA’s Environmental Modeling Center (EMC).