UFS Weather Model

Collage of different weather conditions

The Unified Forecast System (UFS) Weather Model (WM) is a prognostic model that can be used for short- and medium-range research and operational forecasts. It can be run as an atmosphere-only model or as an atmospheric model coupled with one or more additional components, such as a wave or ocean model.

The UFS WM v2.0.0 is the latest public release of this software and represents a snapshot of a continuously evolving system undergoing open development. Key architectural elements of the Weather Model include:

  • The Finite-Volume Cubed-Sphere (FV3) dynamical core is the computational part of an atmospheric model that solves the equations of fluid motion.
  • The Flexible Modeling System (FMS) is a software framework for supporting the efficient development, construction, execution, and scientific interpretation of atmospheric, oceanic, and climate system models. It is used for functions such as parallelization. 
  • The Common-Community Physics Package (CCPP) provides a framework and library of physics schemes that support interoperable atmospheric physics. Atmospheric physics is a set of numerical methods approximating the effects of small-scale processes such as clouds, turbulence, radiation, and their interactions. 
  • Stochastic Physics schemes apply randomized perturbations to the physical tendencies, or physical parameters, of a model in order to compensate for model uncertainty. 
  • The NOAA Environmental Modeling System (NEMS) is a software infrastructure that supports NCEP/EMC’s forecast products. In particular, the model driver is used to organize calls to various WM components hierarchically.

The Weather Model is currently used in NOAA’s operational Global Forecast System (GFS). Additionally, the UFS Short-Range Weather (SRW) Application uses the fully coupled Weather Model in its v2.0.0 release (June 2022), and the UFS Medium-Range Weather (MRW) Application can run the WM in coupled or atmosphere-only mode. 

The UFS WM code is portable and can be used with Linux and Mac operating systems and with Intel and GNU compilers. It has been tested on a variety of platforms widely used by atmospheric scientists, including NOAA’s Hera system, the National Center for Atmospheric Research (NCAR) Cheyenne system, and the Mississippi State University (MSU)/NOAA Orion system.

Those wishing to contribute to the development of the UFS WM should become familiar with the procedures for running the model as a standalone component and for executing the regression tests described in the UFS WM GitHub wiki to make sure that no inadvertent changes to the results have been introduced during the development process.

Support for the UFS WM is provided through the UFS WM Forum by the Developmental Testbed Center (DTC) and other groups involved in UFS development, including NOAA’s Environmental Modeling Center (EMC), NOAA research laboratories (GFDL, NSSL, ESRL, and AOML), the Earth Prediction Innovation Center (EPIC), and NCAR. UFS users and developers are encouraged not only to post questions but also to help address questions posted by other members of the community. More information about the UFS Community can be found on the UFS Community Portal

Links:

UFS-Weather-Model

Read Me File

Releases

Release Date: 06/23/2022

Release Description: The SRW Application v2.0.0 includes a prognostic atmospheric model, pre- and post-processing, and a community workflow for running the system end-to-end. These components are documented within this User’s Guide and supported through a community forum (https://forums.ufscommunity.org/). New and improved capabilities for this release include the addition of a verification package (METplus) for both deterministic and ensemble simulations and support for four Stochastically Perturbed Perturbation (SPP) schemes. Future work will expand the capabilities of the application to include data assimilation (DA) and a forecast restart/cycling capability.

Documentation:

Release Date: 09/16/2021

Release Description: Bug fix release. There is a full description of the version 1.0.1 release here.

Documentation:

Release Date: 03/04/2021

Release Description: The UFS Short-Range Weather (SRW) Application targets predictions of atmospheric behavior on a limited spatial domain and on time scales from less than an hour out to several days. The SRW Application version 1.0 release includes a prognostic atmospheric model, pre- and post-processing, and a community workflow for running the system end-to-end. More details are provided here.

Short-Range Weather App User Guide

User Support