Public Information Statement
Issued by NWS National HQ
Issued by NWS National HQ
263 NOUS41 KWBC 181315 PNSWSH Service Change Notice 24-98 National Weather Service Headquarters Silver Spring MD 915 AM EDT Fri Oct 18 2024 To: Subscribers: -NOAA Weather Wire Service -Emergency Managers Weather Information Network -NOAAPort Other NWS Partners, Users and Employees From: Greg Schoor, Chief Marine, Tropical, and Tsunami Services Branch Subject: The Coastal Waters Forecast Product from the Weather Forecast Office (WFO) in Guam Will Include Additional Wave Information on or about November 4, 2024 The National Weather Service (NWS) Weather Forecast Office (WFO) in Guam (GUM) will start including wave height, period, and direction in the Coastal Waters Forecast (CWF) text product for Guam and the Commonwealth of the Northern Mariana Islands (CNMI) coastal waters on or about November 4, 2024. The initial nationwide implementation that did not include Guam was completed in the Spring of 2024 and can be referenced in Service Change Notice (SCN) 24-17, with further information about the changes to the CWF included as a reference. This implementation will enable WFO Guam to provide the following enhanced and detailed wave information in the CWF: 1) Significant wave height (mandatory) with ranges (optional): - Seas 6 ft. (wave height) - Seas 4 to 6 ft. (wave height with range) 2) Wave detail information - height, period, and direction (single values) for one or more wave systems: - Wave Detail: E 4 ft at 5 seconds and NE 2 ft at 13 seconds. 3) The terms "wind wave" and "swell" will no longer be utilized in the CWF. While once helpful for describing wave characteristics before the advent of modern wave models, continued use of these terms hinders the standardization of more informative wave terminology, such as height, period, and direction, produced by wave models. The Coastal Waters Forecast (CWF) product for WFO Guam can be found at the following link: https://forecast.weather.gov/product.php?site=CRH&product=CWF&is suedby=GUM Table 1: NWS Office that Will Issue CWF Containing the Wave Component WFO WMO Header AWIPS ID ---------- ---------- -------- Tiyan, Guam FZMY50 PGUM CWFGUM Further information on the CWF Wave Component can be found in the Product Description Document available at the following link: https://nsdeskdev.servicenowservices.com/api/g_noa/nwspc/res2/d7 f8c71d87111e10fd6c0f280cbb3541 On NWS websites, clicking on coastal areas of the Watches, Warnings and Advisories (WWA) map will display the marine forecast with wave details. However, selecting a point on the secondary map does not include detailed wave terminology, though this feature is expected in a future update. If you have questions or comments, please contact: Melinda Bailey NWS National Marine Program Manager Silver Spring, MD melinda.bailey@noaa.gov or Elizabeth Vickery Regional Operational Services Meteorologist NWS Pacific Region Headquarters Honolulu, HI elizabeth.vickery@noaa.gov National Service Change Notices are online at: https://www.weather.gov/notification/