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 agreed-upon 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 also share agreed-upon infrastructure such as model coupling tools and workflow software.
The UFS supports configurations for applications with varying levels of complexity. Unified infrastructure at the application level allows for coupled interactions among components while retaining:
- the ability to run simulations with different collections of model and workflow components,
- the ability to substitute prognostic model components with prescribed data components, and
- the ability to run ensembles and multiple instances of model components.
Unified infrastructure at the workflow level allows for runs with or without pre-processing, data assimilation, forward forecasting, reanalysis and reforecasting, ensemble and probabilistic processing, post-processing, and verification.
The UFS effort is working toward a verification and validation plan that spans UFS applications and supports evidence-based decision making. Infrastructure to support the execution of the plan is being developed in parallel to the plan itself.
A balance is sustained between the need to periodically update and synchronize components and infrastructure and the need for developers to work in their areas of interest without affecting or being affected by development in other areas. Areas of interest range from a single column physics routine to fully coupled applications.