Service Change Notices 26-47 and 26-48: The legacy slate of mesoscale models, including the NAM, SREF, HREF, HiresW, and NAM MOS, will be terminated effective August 31, 2026, to be replaced by RRFS and REFS.
Links to each Service Change Notice are provided below:
SCN 26-47: Termination of the NAM, SREF, HREF, HiresW, and NAM MOS: Effective August 31, 2026
[SCN 26-48: Implementation of the Rapid Refresh Forecast System (RRFS) and RRFS Ensemble Forecast System (REFS): Effective August 31, 2026] (https://www.weather.gov/media/notification/pdf_2026/scn26-48_RRFS_and_REFS_Implementation.pdf)
For those not aware, the RRFS and REFS are the Rapid Refresh Forecast System and RRFS Ensemble Forecast System respectively and are run on 3-kilometer resolution grids covering a North American domain encompassing that of all the legacy models. The RRFS will run hourly out to 84 hours and the REFS will run ever six hours out to 60 hours. From SCN 26-48: "A real-time feed of RRFS and REFS will be available on or about June 9, 2026." Further information can be found in the linked documents.