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Home » Focus Areas » Unified Forecast System

Unified Forecast System

GSL is part of this ongoing unification effort to move from the existing NOAA prediction systems to the Unified Forecast System (UFS) is a major multi-year undertaking. Benefits of this NOAA model unification to the UFS will be far-reaching and include many aspects such as:

The most overarching benefit to the U.S. weather enterprise is focusing human resources and expertise from across the meteorological community on a single, shared system and avoidance of duplicative efforts. The evolution toward this developmental paradigm reflects a broad consensus that only with such a shared system, and an associated shared collective expertise, can we maximize forecast skill across the many model applications.

FV3 Model Fields


GSL leads the development of the coupled meteorology-chemistry model WRF-Chem in collaboration with many national and international scientists. WRF-Chem - is a-state-of-the-art fully coupled meteorology-chemistry model to simulate air quality, atmospheric composition and chemistry-meteorology interactions ranging from local to continental scales. The full description of the model can be found in:

GEFS-Aerosols - A coupled global aerosol forecasting model.

Rapid Refresh Forecast System

GSL, NCEP/EMC, and other partners are working together on a project to design a single-model, convection-allowing, ensemble-based data assimilation, and forecasting system called the Rapid Refresh Forecast System (RRFS). This project aims to develop advanced high-resolution data-assimilation techniques and ensemble-forecasting methods while supporting the unification and simplification of the NCEP modeling suite around the FV3 model.

Subseasonal-to-Seasonal Prediction - Our research in this area addresses issues related to sources of predictability, forecast system component closures, and model physics development. We work closely with the coupled Unified Forecast System to improve this model’s forecast skill by identifying sources of model errors, reducing model biases and better representing longer-lived phenomena like the Madden-Julian Oscillation and its teleconnections.The coupled FIM-iHYCOM model is part of a multi-institutional ensemble-generating real time subseasonal (weeks 3-4) prediction system, see results at

Hurricane Weather Research and Forecast (HWRF) model -- HWRF is a coupled atmosphere-ocean-wave model used for tropical cyclone research and NOAA operations. It provides realtime guidance to the National Hurricane Center. Community releases can be found here.