The Weeks 3-4 Program within the NWS Office of Science and Technology Integration (OSTI) Modeling Program Division was established in 2016 as part of an agency-wide initiative to improve extended-range weather outlooks with a 5-year initial funding package from the U.S. Congress. This kickstarted activities within two NOAA Line Offices, the National Weather Service (NWS) and the Office of Oceanic and Atmospheric Research (OAR), with the following four key areas of focus: 1) Extending numerical guidance out in time; 2) Building reforecast and reanalysis capabilities; 3) Innovating forecast products; and 4) Supporting applied research in the subseasonal forecast range.
NWS’s Weeks 3-4 Program has supported the development and implementation of the subseasonal Global Ensemble Forecast System (GEFS) Version 12 by the Environmental Modeling Center (EMC) of NCEP in September 2020. The currently operational GEFSv12 is a major upgrade over its prior version implemented in 2015 and features an FV3 dynamical core, increased forecast length to 35 days, increased model resolution to 25 km and ensemble to 31 members, coupling with waves and aerosol components, and a 20 year (2000-2019) reanalysis and 31 year (1989-2019) reforecast dataset.
Under the Unified Forecast System (UFS) Research to Operation Project (UFS R2O), GEFSv13 is being built as the first global coupled model for operational subseasonal forecasts, featuring a FV3 atmosphere with the Common Community Physics Package (CCPP), ocean (MOM6), land surface (Noah-MP), sea ice (CICE6), and ocean waves (WW3) coupled via the Community Mediator for Earth Prediction Systems (CMEPS) and supporting a 31-year (1994-2024) reanalysis (UFS Replay) and reforecast dataset and forecast lengths out to 48 days.
The Weeks 3-4 Program has also supported multi-year projects at the Climate Prediction Center (CPC) that cover a range of focus areas such as Arctic sea ice prediction, drought monitoring and prediction, Global Tropics Hazards Outlook, Excessive Heat Outlook, and the use of various consolidation tools to improve Weeks 3-4 Temperature and Precipitation Outlook. Those projects support the improvement of operational forecast products at CPC and the dissemination of more skillful forecast guidance to the public.
The Weeks 3-4 Program also collaborates with the S2S Program, Climate Testbed, Joint Technology Transfer Initiative (JTTI), and Earth Prediction Innovation Center (EPIC) Program at the Weather Program Office of NOAA OAR on transitioning research to operations. In addition, it promotes advancement of coupled data assimilation within the Joint Effort for Data Assimilation Integration (JEDI) framework, reanalysis and reforecasts, S2S diagnostics and evaluation tools such as MetPlus and EMC’s Verification System (EVS), and S2S science initiatives with other programs and federal agencies from ICAMS
Contact Information:
Yan Xue (Program Manager) at yan.xue@noaa.gov
Steven Simon (Deputy Program Manager) at steven.simon@noaa.gov
Jason Anderson (Deputy Program Manager) at jason.r.anderson@noaa.gov
