National Weather Service United States Department of Commerce

 

National Weather Service Wilmington NC

Marine Zone Expansion to 60 NM Offshore

 


 

OVERVIEW

 

Beginning on or about March 3, 2026, National Weather Service (NWS) Weather Forecast Office (WFO) Wilmington, NC (ILM) will assume forecast, watch, and warning responsibility for the coastal waters from Surf City, NC to South Santee River, SC from 20 to 60 Nautical Miles (NM) offshore. Routine forecast services for these waters were previously the responsibility of the Ocean Prediction Center (OPC), with warning responsibility divided between WFO ILM and OPC. This change is part of a regional improvement that will result in all forecasts and warnings for coastal waterways within 60 NM of shore originating from the local WFO across the entire Contiguous United States (CONUS). There will be no change to the current forecast and warning services provided by WFO ILM for coastal waterways within 20 NM of shore..

JUSTIFICATION

The coastal waterways are lifelines of commerce in the eastern Carolinas, frequented by commercial, recreational, and research vessels year-round. Major shipping lanes pass just off our coast, with ships passing just east of Cape Fear to minimize the distance needed to traverse between critical ports in the Northeast/Mid-Atlantic and the Southeast. Additionally, fishermen often leave local ports bound for offshore fishing sites such as artificial reefs and the Gulf Stream. These activities primarily take place within 60 NM of shore, with mariners depending on reliable weather forecasts from the National Weather Service to ensure the safety of themselves and their crew, passengers, and cargo while on the water.

 

The Graphic above shows that a significant amount of cargo and tanker vessels traverse about 15-60 NM offshore of the the coast of the Carolinas. Expanding WFO ILM forecast and warning responsibility to 60 NM offshore will thus cover significantly more commercial traffic. 

 

With the redesignation of all forecast and warning responsibility for the coastal waters within 60 NM of shore to the local WFO, users will experience these benefits:

  1. Improved forecast service continuity, with local WFO’s now responsible for issuing routine forecasts and warnings for all marine waters out to 60 NM offshore for the entire CONUS.

  2. Increased number of forecast parameters with temperature, precipitation chances, and weather type among the parameters that are now available for mariners from 20 to 60 NM offshore out to 5 days in the future.

  3. Improved forecast resolution, with point and click forecast capability now enabling mariners to get hourly forecasts for specific points (such as offshore artificial reefs) anywhere within 60 NM of shore out to 5 days in the future.

  4. Expanded suite of short and long-fused watch/warning and advisory products to alert mariners to the potential for a variety of hazardous weather conditions.

  5. WFO’s now have the capability to deliver Impact-based Decision Support Services (IDSS) to partners in support of incident response for incidents that occur anywhere within 60 NM of shore. 

 

ZONE CHANGE DESCRIPTIONS

 

The areal extent of the new marine zones was largely established by maintaining the current location and orientation of the along-coast zone breaks for the nearshore marine zones and extending them to meet a line which runs approximately 60 NM off the coast. The following graphics and table illustrate the new area covered by these zones.

 

 

 

Marine Zones that were the responsibility of NWS Wilmington NC (NWS ILM) before the expansion

 

 

 

Offshore Marine Zones that were the responsibility of the Ocean Prediction Center (OPC) before the expansion

 

The above graphic shows the previous alignment of marine zones with top map showing zones that were the responsibility of the local WFO. 

The above graphic shows the NEW alignment of marine forecast zones with light and dark blue zones now being the responsibility of the local WFO. All coastal waters to 60 NM offshore  from Surf City, NC to the South Santee River, SC will now receive forecasts and warnings from NWS Wilmington, NC (NWS ILM).

 

AREA PREVIOUS ZONE NAME(S) PREVIOUS ZONE NUMBER(S) NEW ZONE NAME NEW ZONE NUMBER
Ocean Waters from the Onslow/Pender County Line to the tip of Cape Fear and then south to NC/SC border (Little River Inlet), from 20 to 60 NM offshore

Waters from Surf City to Cape Fear NC from 20 to 40 nm (ILM)

 

Waters from Cape Fear NC to Little River Inlet SC from  20 to 40 nm (ILM)

Cape Hatteras to Cape Fear to 100 NM Offshore (Partial, OPC)

Cape Fear to 31N out to 1000 Fathoms (Partial, OPC)

AMZ270

 

 

AMZ272

 

ANZ833

 

 

ANZ835

 

Waters from Surf City NC to Little River Inlet SC from 20 to 60 NM AMZ280
Ocean Waters from SC/NC border (Little River Inlet) south to Georgetown/Charleston County Border (South Santee River) from 20 to 60 NM offshore

Waters from Little River Inlet SC to Murrells Inlet SC from 20 to 40 nm (ILM)

Waters from Murrells Inlet SC to South Santee River SC from 20 to 40 nm (ILM)

 

Cape Fear to 31N out to 1000 Fathoms (Partial, OPC)

AMZ274

 

 

AMZ276

 

ANZ835

Waters from Little River Inlet SC to South Santee River SC from 20 to 60 NM AMZ284

 

FORECAST RESOURCES

WFO ILM's (NWS Wilmington NC) products affected by these changes are listed in the table below:
 
Product Name WMO Header AWIPS ID
Coastal Waters Forecast FZUS52 CWFILM
Hazardous Weather Outlook FLUS42 HWOILM
Marine Weather Message WHUS72 MWWILM
Special Marine Warning WHUS52 SMWILM
Marine Weather Statement FZUS72 MWSILM
Watch County Notification WWUS62 WCNILM

 

Marine users have several options for directly receiving official National Weather Service forecasts and warnings:
 
 

NOAA Weather Radio

 

 

One of the most immediate and reliable ways to receive forecasts, watches, and warnings for the waterways of eastern North Carolina is through NOAA Weather Radio. The following table and map outline the best transmitter for area waterways:

 

AREA TRANSMMITTER LOCATION TRANSMITTER FREQUENCY

Coastal Waters from Onslow/Pender County Border Line (Surf City NC) south to Apache Pier in Horry County SC (south of Little River Inlet SC)

Covers AMZ250, AMZ252, and portions of AMZ254 and AMZ280

Winnabow, SC (KHB-31) 162.550 mhz

Coastal Waters from Shallotte River Inlet in Brunswick County NC (north of Little River Inlet SC) south to Winyah Bay in Georgetown County SC (north of South Santee River SC)

Covers AMZ254 and portions of AMZ252 and AMZ256

Aynor, SC      (KEC-95)

162.400 mhz

Coastal Waters from Myrtle Beach in Horry County SC south to South Santee River and continues south to Bulls Bay in Charleston County SC.

Covers AMZ256 and portions of AMZ254

Georgetown, SC (WNG-628) 162.500 mhz

 

 

 

Online

 

 

Routine forecasts and warnings for mariners in eastern North Carolina waters can be found online at weather.gov/ilm/marine.

Alternatively, to get the forecast for a specific point, visit weather.gov/marine/point and click on the map or enter you lat/lon.

 

Telephone

 

Recorded area marine forecasts can be accessed by calling (910)762-4289 Press 0 then Press 2.

 

CONTACT

 

Please submit any questions or comments to:

Steve Pfaff
Meteorologist-in-Charge
National Weather Service
Wilmington NC
2015 Gardner Dr.
Wilmington, NC 28405
(910)762-4289
steven.pfaff@noaa.gov

 

CLICK HERE FOR THE OFFICIAL SERVICE CHANGE NOTICE (not available yet)