Public Information Statement
Issued by NWS National HQ
Issued by NWS National HQ
476 NOUS41 KWBC 301545 PNSWSH Service Change Notice 25-76 National Weather Service Headquarters Silver Spring MD 1145 AM EDT Thu Oct 30 2025 To: Subscribers: -NOAA Weather Wire Service -Emergency Managers Weather Information Network -NOAAPort Other NWS Partners, Users, and Employees From: Kevin Stone, Team Lead Aviation Weather Services Program Subject: Changes to International Operational Meteorological (OPMET) Data Distribution on or about December 3, 2025 The Washington Inter-Regional OPMET Gateway (IROG), also known as the National Weather Service Telecommunications Gateway (NWSTG), is updating traditional Alpha-Numeric Content (TAC) for its international OPMET distribution. As the Washington IROG is updating the current TAC database in preparation for International Civil Aviation Organization (ICAO) Meteorological Information Exchange Model (IWXXM) dissemination. Currently, 26 non-ICAO compliant collectives are being distributed internationally. These will be replaced with approximately 380 ICAO compliant native collectives. Changes will start on or about December 3, 2025. See link below for the complete list of discontinued items and their replacements that will be added to the Washington IROG. This update is planned for late this year into early 2026. The ICAO-compliant collectives are expected to be added slowly over a period of time to ensure users are not losing data. In the event that the implementation date is declared a Critical Weather Day (CWD), an Enhanced Caution Event (ECE), or other significant weather is occurring or is anticipated to occur, implementation will take place at 1400 UTC on the next weekday not declared a CWD and when no significant weather is occurring. An example follows: SiteID New Replaces FCNT31 KWBC: (this is an example of a non- compliant US collective being deleted) containing the locations BGBW, BGCO, and BGGH. And will be replaced with the following native ICAO compliant collectives below. BGBW - FCGL31 BGGH BGCO - FCGL45 BGGH BGGH - FCGL31 BGGH / FCGL45 BGGH Users can view the list of non-compliant collectives with their replacement collectives in the link below. Non-compliant collectives : https://www.weather.gov/source/datamgmt/Non- CompliantICAO.txt If you have comments or questions, please contact: Michael L. Graf Meteorologist/International Liaison NWS Headquarters Silver Spring, MD 304-268-0691 michael.graf@noaa.gov National Service Change Notices are online at: https://www.weather.gov/notification