Public Information Statement
Issued by NWS National HQ
Issued by NWS National HQ
603 NOUS41 KWBC 262055 PNSWSH Service Change Notice 24-92 National Weather Service Headquarters Silver Spring, MD 455 PM EDT Thu Sep 26 2024 TO: Subscribers: -NOAA Weather Wire Service -Emergency Managers Weather Information Network -NOAAPORT Other NWS partners and NWS employees FROM: Bruce Entwistle Chief, Aviation and Space Weather Services Branch Subject: Retirement of the Airmens Meteorological Information (AIRMET) over CONUS: Effective on or about January 27, 2025 Effective on or about January 27, 2025 at 1900 Universal Coordinated Time, the Traditional Alphanumeric Code (TAC) AIRMET over the six regions of the Contiguous United States (CONUS) will be retired. The NWS will continue to provide the Graphical AIRMET (G-AIRMET) over the CONUS. The product is currently located at https://aviationweather.gov/gfa/#gairmet. The AIRMET is a description of the occurrence or expected occurrence of specified en-route aviation weather phenomena at intensities less than the issuance of a Significant Meteorological Information (SIGMET) warning would require. In 2010, the Aviation Weather Center (AWC) began the operational production of the G-AIRMET over the CONUS. G-AIRMETs are issued based on the same criteria as TAC AIRMETs. The G-AIRMET is disseminated as a message in Binary Universal Form for the Representation of meteorological data (BUFR) format and as graphics via the website referenced above. In 2021, the NWS also began transmitting the G-AIRMET in eXtensible Markup Language (XML) format. The G-AIRMET format can be used to display graphical forecasts of en-route weather hazards and to generate a text message tailored to user needs. A Federal Aviation Administration (FAA) working group recommended the retirement of the TAC AIRMET and transition to the G-AIRMET. The FAA convened a Safety Risk Management Panel (SRMP) to evaluate any hazards associated with the retirement of the TAC AIRMET. Based on the working group recommendation and the SRMP results, the FAA has formally requested the NWS retire the TAC AIRMET and produce only the G-AIRMET for the CONUS. TAC AIRMETs for Alaska and Hawaii will not be affected at this time. The 18 CONUS TAC AIRMETs affected are listed below: WAUS41 (BOS) Sierra, Tango, and Zulu WAUS42 (MIA) Sierra, Tango, and Zulu WAUS43 (CHI) Sierra, Tango, and Zulu WAUS44 (DFW) Sierra, Tango, and Zulu WAUS45 (SLC) Sierra, Tango, and Zulu WAUS46 (SFO) Sierra, Tango, and Zulu Examples of G-AIRMET XML messages can be found at: https://tgftp.nws.noaa.gov/data/raw/lw/. More information about XML G-AIRMETs can be found in the Product Description Document (PDD) at: https://www.weather.gov/media/notification/ref/pdd_xml_g- airmet.pdf. For questions regarding the TAC AIRMET retirement, please contact: Kevin Stone Meteorologist, Aviation and Space Weather Services Branch National Weather Service Headquarters Silver Spring, MD 20910 Phone: 301-427-9363 Email: kevin.stone@noaa.gov NWS Service Change Notices are online at: https://www.weather.gov/notification/