National Weather Service Charleston, SC Zone Changes for 2026

WFO Charleston SC is making minor adjustments to public, fire weather, and marine zone shapefiles along the South Carolina and Georgia coasts in order to improve partner service and better match physical boundaries

Issues

1) The current shapefiles are unnecessarily complex, inconsistently handling features such as rivers, sounds, sandbars, islands, and piers. This can create confusion about what areas are considered marine and what are considered land for forecast purposes.

2) The current shapefiles do not reflect current physical boundaries. Processes such as coastal erosion, shoaling, and sand bar migration have resulted in features being incorrectly represented by our current shapefiles.

Solution

NWS Charleston has conducted a thorough review of zone boundaries along the South Carolina and Georgia coasts. The following adjustments have been made in order to

1. Remove areas that are not consistently dry (such as sandbars) from land zones.

2. Consistently include large inlets/sounds with their adjacent marine zones, and absorb very small creeks and rivers into the surrounding land zones.

3. Adjust zone boundaries to reflect current land extent (accounting for erosion and changing shorelines) and update zone numbers accordingly.

The Shapefile Changes are Shown Below:

Map of Previous Zone Boundaries	Map of New Zone Boundaries

The Following Zone Numbers Will be Adjusted as Part of This Change:

Zone Name	Previous Zone Number	New Zone Number*
Charleston	SCZ050	SCZ150
Tidal Berkeley	SCZ052	SCZ152
Coastal Colleton	SCZ049	SCZ149
Beaufort	SCZ048	SCZ148
Coastal Jasper	SCZ051	SCZ151
Inland Jasper	SCZ047	SCZ147

*effective on or around March 3rd, 2026

Zone Name	Previous Zone Number	New Zone Number*
Inland Chatham	GAZ118	GAZ218
Coastal Chatham	GAZ119	GAZ219
Inland Bryan	GAZ116	GAZ216
Coastal Bryan	GAZ117	GAZ217
Inland Liberty	GAZ138	GAZ238
Coastal Liberty	GAZ139	GAZ239
Inland McIntosh	GAZ140	GAZ240
Coastal McIntosh	GAZ141	GAZ241

*effective 4pm (EST) Tuesday, March 3rd, 2026

Marine Zone Name	Previous Zone Number	New Zone Number*
Charleston Harbor	AMZ330	AMZ340
Coastal Waters from South Santee River to Edisto Beach SC out 20 NM	AMZ350	AMZ360
Coastal Waters from Edisto Beach SC to Savannah GA out 20 NM	AMZ352	AMZ362
Waters from Savannah GA to Altamaha Sound GA out 20 NM, including Grays Reef National Marine Sanctuary	AMZ354	AMZ364