The National Oceanic and Atmospheric Administration (NOAA) has revealed that it is upgrading its Global Forecast System (GFS) to improve hurricane genesis forecasting, modeling for snowfall location, heavy rainfall forecasts, and overall model performance.
The GFS will be coupled with a global wave model called WaveWatch III, which will extend current wave forecasts from 10 days out to 16 days, and improve the prediction of ocean waves forced by the atmosphere.
Coupling the GFS and wave models will streamline the National Centers for Environmental Prediction (NCEP) production suite by consolidating atmospheric and wave forecast data and distributing them together. The GFS resolution will increase by doubling the number of vertical levels, from 64 to 127. Improvements to atmospheric physics will enhance snow and precipitation forecasting capabilities in this latest upgrade as well.
NOAA is also modernizing the Global Data Assimilation System (GDAS) to allow the model to ingest more data from geostationary and polar-orbiting satellites, as well as flight-level wind, temperature and moisture observations from aircraft.
“These upgrades are part of the Next Generation Global Prediction System within the Unified Forecast System (UFS) framework, which is an ongoing effort to leverage the expertise of the broader weather community and expedite the research to operations pathway,” said Vijay Tallapragda, chief of the Modeling and Data Assimilation Branch at NOAA’s Environmental Modeling Center (EMC). “By coupling the WaveWatch III and GFS models, we will extend current wave forecasts and integrate wave forecasting into the global model to streamline model products.”
EMC conducted retrospective and real-time testing, covering part of the 2018 hurricane season and the entire period from May 10, 2019 to the present, for a comprehensive evaluation of the model upgrades. This latest version of the model, called GFSv16, showed improved forecast skills in many areas, including hurricane genesis lead times, snowfall forecasting, and the prediction of extreme rainfall events.