Public Information Statement
Issued by NWS National HQ
Issued by NWS National HQ
878 NOUS41 KWBC 201555 PNSWSH Public Information Statement 25-73 National Weather Service Headquarters Silver Spring MD 1055 AM EST Thu Nov 20 2025 To: Subscribers: -NOAA Weather Wire Service -Emergency Managers Weather Information Network -NOAAPORT Other NWS Partners, Users and Employees From: Geoff Manikin Chief, Statistical Modeling Division NWS Office of Science and Technology Integration Meteorological Development Laboratory Subject: Soliciting comments on the proposed termination of the North American Mesoscale Forecast System (NAM) Model Output Statistics (NAM MOS) products, through Monday, December 22, 2025. The National Weather Servicess Meteorological Development Lab (MDL) is soliciting comments on the proposed termination of the NAM MOS through December 22, 2025. NAM MOS products may sunset in March 2026, as the Environmental Modeling Center (EMC) at the National Centers for Environmental Prediction (NCEP) is proposing to discontinue the NAM. A Public Information Statement regarding the NAM retirement was released by EMC on June 26, 2025: https://www.weather.gov/media/notification/pdf_2025/pns25- 41_RRFS_legacy_model_cessation.pdf Because the NAM MOS is a downstream product with dependencies on output from the underlying model, this will require that all NAM MOS products be terminated when the NAM itself is discontinued. Additionally, some of MDLs Localized Aviation MOS Program (LAMP) products use NAM MOS forecasts as inputs, including 1-h convection and lightning probability (CONUS and Alaska), 1-h convection and lightning potential (CONUS and Alaska), and 1-h Probability of Precipitation (CONUS). These LAMP products will use GFS MOS in place of NAM MOS as a temporary solution until these elements are recalibrated without NAM MOS input. Retirement of the NAM and associated MOS products is possible in March 2026. Going forward, it is recommended that users of NAM MOS transition to MOS that is based on the Global Forecast System (GFS MOS) or to the National Blend of Models (NBM) text products as substitutes. If this change is approved, a Service Change Notice will be issued at least 30 days prior to the proposed termination. For comments or questions regarding this proposed change, please contact: Geoff Manikin Chief, Statistical Modeling Division MDL/Silver Spring, Maryland geoffrey.manikin@noaa.gov or Mark Antolik MOS Technical Lead MDL/Silver Spring, Maryland mark.antolik@noaa.gov Details about the GFS MOS can be found at: https://vlab.noaa.gov/web/mdl/gfs-mos And the NBM text products at: https://vlab.noaa.gov/web/mdl/nbm-text-products Further information about the Localized Aviation MOS Program (LAMP) is available at: https://vlab.noaa.gov/web/mdl/lamp National Public Information Statements are online at: http://www.weather.gov/notification/