552
NOUS41 KWBC 302040
PNSWSH

Service Change Notice 25-12
National Weather Service Headquarters Silver Spring MD
340 PM EST Thu Jan 30 2025

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: Replacing the Imperial Unit Feet with the Metric Unit
Meter in National Marine Center High Seas Text and Graphical
Products on or about May 15, 2025

On or about May 15, 2025, the National Weather Service (NWS)
National Centers for Environmental Predictions (NCEP) Ocean
Prediction Center (OPC), the National Hurricane Centers (NHC)
Tropical Analysis and Forecast Branch (TAFB), and NWS Pacific
Region (PR) will replace the imperial unit feet with the
metric unit meter for wave heights in text and graphical
products for the high seas.  Responses from a recent public
comment period indicated that users prefer wave information in
high seas products in units of meters.Additionally, this
change will align NWS high seas products with international
partners and mariners and with existing high seas products.

This change does not include the NWS Coastal Waters Forecasts
(CWF) products within 60 nautical miles (NM) of the U.S.
coastline and the forecasts over the Great Lakes.  This also
does not affect the offshore zones that mostly go beyond 60 NM
of the coast.

Text products in this change include:

AWIPS    WMO Heading    Geographic Descriptor
Identifier
---------  ----------    --------------------
HSFAT1    FZNT01 KWBC    High Seas Forecast METAREA IV

HSFAT2    FZNT02 KNHC    High Seas Forecast ATLANTIC
   FROM 07N TO 31N W OF 35W INCLUDING
   CARIBBEAN SEA AND GULF OF MEXICO

HSFEPI    FZPN02 KWBC    High Seas Forecast METAREA XII

HSFEP1    FZPN01 KWBC    High Seas Forecast PACIFIC N OF 30N
   AND S OF 67N E OF A LINE FROM BERING
   STRAIT TO 50N 160E

HSFEP2    FZPN03 KNHC    High Seas Forecast E PACIFIC FROM THE
   EQUATOR TO 30N E OF 140W AND 03.4S TO
   THE EQUATOR E OF 120W

HSFNP    FZPN40 PHFO    High Seas Forecast NORTH PACIFIC
   EQUATOR TO 30N BETWEEN 140W AND 160E

HSFSP    FZPS40 PHFO    High Seas Forecast SOUTH PACIFIC
   EQUATOR TO 25S BETWEEN 120W AND 160E

TCMAT1-5  WTNT[21-25] KNHC  Atlantic Tropical Cyclone
     Forecast/Advisory (NHC)

TCMAT1-5  WTNT[21-25] KWNH  Atlantic Tropical Cyclone
    Forecast/Advisory (WPC)

TCMCP1-5  WTPA[21-25] PHFO  C Pacific Tropical Cyclone
    Forecast/Advisory (CPHC)

TCMEP1-5  WTPZ[21-25] KNHC  E Pacific Tropical Cyclone
    Forecast/Advisory (NHC)

TCMEP1-5  WTPZ[21-25] KWNH  E Pacific Tropical Cyclone
    Forecast/Advisory (WPC)

Graphical products in this change include:

Ocean Prediction Center:
Atlantic and Pacific wind/wave analyses

National Hurricane Center/Tropical Analysis and Forecast Branch:
Atlantic and Pacific Sea State analyses

National Hurricane Center/Tropical Analysis and Forecast Branch:
Atlantic and Pacific 24-hr, 48-hr, and 72-hr Wind/Wave forecasts

National Hurricane Center/Tropical Analysis and Forecast Branch:
Atlantic and Pacific High Wind/Seas forecasts

Honolulu Weather Forecast Office (WFO HFO):
Wind/Wave analysis and 24-hr, 48-hr, and 72-hr forecast charts

Wave heights in the National Digital Forecast Database (NDFD)
gridded binary (GRIB) files are in meters.  The NDFD Graphical
Display at digital.weather.gov will continue to be able to be
displayed in feet or meters.

A brief description of the change can be found at:

https://ocean.weather.gov/proposed-meters.php

You can submit comments on this change at:

https://ocean.weather.gov/survey-proposed-meters/index.php

You can also submit comments to:

Darin Figurskey
Operations Branch Chief
Ocean Prediction Center
College Park, MD
darin.figurskey@noaa.gov

John Hurley
Director of Operations
WFO Honolulu
Honolulu, HI
john.hurley@noaa.gov

Chris Landsea
Chief
NHC Tropical Analysis and Forecast Branch
Miami, FL
chris.landsea@noaa.gov

Melinda Bailey
Marine Program Manager
National Weather Service Headquarters
Silver Spring, MD
melinda.bailey@noaa.gov

National Service Change Notices are online at:

https://www.weather.gov/notification/