Revolutionizing the High Seas Forecast Product

Revolutionizing the High Seas Forecast Product

The National Weather Service (NWS) wants your input on a proposal to revolutionize the format and delivery of wind, wave, and visibility hazard information for high seas areas in the North Atlantic and Pacific Oceans! Examples of the proposed changes can be found below. You can submit your feedback here or send an email to wayne.presnell@noaa.gov. Public comments will be accepted through May 3, 2023. However, we strongly recommend that you check out the background and proposal information below for more details first.

This proposal includes potential changes to the format of the NWS High Seas Forecast (HSF) text products to reference polygons that represent a hazard area over a 24 hour forecast period rather than at a snapshot in time as they are currently identified. These areas will be determined using gridded 10-m wind and significant wave height forecasts currently available in the National Digital Forecast Database (NDFD) as well as visibility forecasts. However, the gridded forecast and polygon hazard data are proposed to be made available in the Universal Hydrographic Data Model format known generically as “S-100”. More information on the S-100 format can be found here.

Here’s an example of a future wind “hazard” polygons with the gridded wind analysis and forecast information:

Gale, Storm and Hurricane force winds over 24 hours.	Animated loop of 24 hour max of Gale, Storm and Hurricane Force Winds

The NWS is proposing to provide both the detailed gridded wind forecast and the polygon “hazard” area in S-100 format, so that this information can be automatically imported into navigational display systems. Similar gridded forecasts would be available for waves and visibility analyses and forecasts.

The NWS is also proposing to change the format of the HSF text products to reference these polygon “hazard” areas which would be assigned an alphanumeric designator.

Click here for a comparison of a current NWS High Seas Forecast and the proposed High Seas Forecast with the proposed future format.

In addition to the HSF text product, the NWS is proposing to issue “Individual Warnings” for distinct weather systems (i.e., a tropical cyclone, a hurricane-force low, gap winds, etc.). Like the HSF, the Individual Warnings would reference the polygon hazard areas, but the Individual Warnings could be updated at any time of the day instead of on the set HSF issuance cycle. This would allow for the provision of more accurate analyses and forecasts for quickly evolving weather conditions. The proposed future HSF will include a listing of all of the hazard polygons within the METAREA that are included in the active Individual Warnings at the issuance time.

The links in the table below reference examples of the potential future HSF text product and the Individual Warnings to match the graphical representation of the forecast and hazard polygons provided above.

Example: Complete METAREA IV Package: Atlantic High Seas 0600 UTC February 6, 2023
Proposed Future High Seas Forecast Example (METAREA IV)	METAREA IV Example
Proposed Future Individual Warning Examples (METAREA IV)	METAREA IV Hurricane Force Winds
	METAREA IV Storm Force Winds
	METAREA IV Gale Force Winds (Labrador Sea)
	METAREA IV Gale Force Winds (Caribbean Sea)
	METAREA IV Heavy Freezing Spray
	METAREA IV Warning for Visibility

Example: Complete METAREA XII Package: Pacific High Seas 0000 UTC August 28, 2018
Proposed Future High Seas Forecast Example (METAREA XII)	METAREA XII Example
Proposed Future Individual Warning Examples (METAREA XII)	METAREA XII Warning for T.S. Miriam
	METAREA XII Warning for Storm Force Winds
	METAREA XII Warning for Gale Force Winds

To provide comments on the proposed changes to the HSF, including the potential addition of Individual Warnings and geographical hazard information in S-100 format, please use the feedback form: https://ocean.weather.gov/survey-hsf-polygons/

Or send an email to: wayne.presnell@noaa.gov

The NWS will evaluate all comments on the proposed changes to the HSF and determine whether to proceed. If public feedback supports this change, a Service Change Notice will be sent before it goes into effect.

Additional Information

To see all of the NWS marine forecast areas, including High Seas, visit this website.

**National Centers Issuing High Seas Forecasts**
Office	Link
Ocean Prediction Center	https://ocean.weather.gov/
NHC Tropical Analysis and Forecast Branch	https://www.nhc.noaa.gov/marine/
Weather Forecast Office Honolulu	https://www.weather.gov/hfo/HSFNP

For more information on the S-100 format, visit this website.

Visit this website to see the World Meteorological Organization (WMO) Publication Number 558 Part 1, Appendix I.1. “Metareas And Designated National Meteorological And Hydrological Services For The Issue Of Meteorological Maritime Safety Information For The Worldwide Met-Ocean Information And Warning Service” (pages 11-12).

Here is more information about the Worldwide Met-Ocean Information and Warning Service, including a map of worldwide METAREAs and which country is responsible for issuing marine forecasts and warnings.

The specifications of the current NWS HSF product can be found in NWSI 10-311 “Offshore, NAVTEX, High Seas, and Marine Forecast Services”, Section 5 “High Seas Forecast”.

If you have questions regarding the proposal, please contact:

Joseph Sienkiewicz Chief, Ocean Applications Branch

NOAA/NWS Ocean Prediction Center

Email: joseph.sienkiewicz@noaa.gov

or

Dr. Chris Landsea Branch Chief, Tropical Analysis and Forecast Branch

NOAA/NWS National Hurricane Center

Email: chris.landsea@noaa.gov