Unified Forecast System


1) Introduction

The Unified Forecast System (UFS) is a community-based, coupled, comprehensive Earth modeling system. The UFS numerical applications span local to global domains and predictive time scales from sub-hourly analyses to seasonal predictions. It is designed to support the Weather Enterprise and to be the source system for NOAA's operational numerical weather prediction applications.

NOAA is the agency tasked with providing the official weather and climate forecasts and warnings in the United States. First and foremost, the UFS provides a framework to engage the extensive research enterprise in the US. It creates an environment to more efficiently and effectively translate research advances into operational outcomes. The UFS also enables NOAA to simplify its production suite of forecasting models from a great many independent systems, each of which has to be improved and maintained, to a single seamless system.

The UFS community includes researchers, developers and users from NOAA, educational institutions, federal agencies, and the private sector. The UFS supports research and development in the community and accelerates the transition of research successes to operations.

UFS applications share numerical forecast system elements, including Earth-system model components (e.g. atmosphere, ocean, sea ice, land, chemistry, etc.), observation processing, pre-processing, data assimilation, forward forecasting, ensemble and probabilistic processing, and post-processing. The applications share infrastructure such as model coupling tools and workflow software.

Comprehensive and updated news on the Unified Forecast System can be found on the UFS Portal website (still under construction).

2) UFS at NWS

The NWS Research to Operations (R2O) initiative's five year plan is to upgrade the current operational Global Forecast System (GFS) to run as a unified, fully coupled Next Generation Global Prediction System (NGGPS) within NEMS (NOAA Environmental Modeling System) infrastructure. Using advanced high performance computing architectures, the system will incorporate the most recent advances in weather prediction modeling from NOAA and the research community.

  • Implement a weather-scale, fully-coupled NWP System

  • Extend forecast skill beyond 8 to 10 days

  • Improve hurricane track and intensity forecast

  • Extend weather forecasting to 30 days

  • Implement the unified next generation model in regional applications (Rapidly Refreshed Convective-Allowing Ensemble Forecast system, Regional Nested Hurricane Forecast System)

  • For further details see the Applications Plan on the UFS web site.

3) UFS at NCEP : Implementation of FV3GFS

In 2017 the Finite Volume Cubed Sphere (FV3) dynamical core, developed at NOAA’s Geophysical Fluid Dynamics Laboratory, was selected for the new NGGPS/UFS atmospheric model for both global and regional scales. At NCEP, the FV3 dynamical core implementation includes incorporating FV3 into NEMS, and developing advanced physics and data assimilation techniques to match or exceed the skill of pperational Global Forecast System (GFS), and to transition NCEP's mesoscale modeling suite to use FV3. In addition, NOAA/NWS is working with federal partners, universities, and the community to create a fully accessible FV3-based community model, see the UFS Community page and the UFS Weather Model page on GitHub.


The first implementation of the UFS Atmospheric model in NCEP occurred on June 12th 2019 with the implementation of GFS Version 15. The major component of this implementation was to replace the global spectral model in the GFS with the FV3 dynamical core. The operational FV3GFS runs the same physics as the previous GFS, except that the Zhao-Carr microphysics was replaced with the more advanced GFDL microphysics scheme.


More details on the implementation of the GFS V15 with the FV3 dynamic core can be found in the NWS Service Change Notice, on EMC's FV3GFS page on the NWS Vlab site. Comprehensive information on the official evaluation of GFS v15 is available at the EMC Model Evaluation Group’s web site.