National Weather Service United States Department of Commerce

Marine Zone Changes for 2022

Effective April 5, 2022, NWS Corpus Christi will split the two zones that cover the bays and waterways between Baffin Bay and Matagorda Bay into four forecast zones. These new zones will provide added geographic specificity to help marine interests identify which bays and inland waterways are of most concern during hazardous weather.


Overview of Changes

The current configuration for the bays and waterways of the Middle Texas Coast is shown below. It involves Baffin Bay, Nueces and Corpus Christi Bays, and the Upper Laguna Madre grouped into one marine forecast zone (GMZ230) and Copano Bay, Aransas Bay, and San Antonio Bay grouped into another marine forecast zone (GMZ235).


Current marine zones

Image 1. Current marine zones for the bays and waterways between Baffin Bay and Matagorda Bay.


To provide more geographic specificity, WFO Corpus Christi will split GMZ230 into two forecast zones and GMZ235 into two forecast zones. Zones match the tropical cyclone breakpoints, except for the divider between GMZ231 and GMZ232. If the Padre Island National Seashore (PINS) breakpoint were used, tropical cyclone products issued for the Kleberg Islands would result in both GMZ231 and GMZ232 requiring tropical headlines. Using a dividing point different than the PINS breakpoint minimizes the potential for a larger than necessary area being highlighted for tropical cyclone hazards.


Proposed marine zones for the bays and waterways between Baffin and Matagorda Bays

Image 2. Proposed marine zone changes for the bays and waterways between Baffin and Matagorda Bay.

Changes in effect March 31, 2022.



Configuration Change Details

The new configuration will allow for WFO Corpus Christi to provide more geographic specificity to mariners and marine partners when highlighting weather hazards, including severe thunderstorms and marine fog.

These zone changes require partners and users to take appropriate action to receive the new zone products using the Universal Geographic Code (UGC) zone code format listed in Table 1. Products affected by this change are listed in Table 2.

Current Marine Zone Name / Current UGC New Marine Zone Name / New UGC

Table 1: Affected Marine Zones

Bays and Waterways from Baffin Bay to Port Aransas (GMZ230) Baffin Bay and Upper Laguna Madre (GMZ231)
Corpus Christi and Nueces Bays (GMZ232)
Bays and Waterways from Port Aransas to Port O'Connor (GMZ235) Copano, Aransas, and Redfish Bays (GMZ236)
San Antonio, Mesquite, and Espiritu Santo Bays (GMZ237)


Product Name WMO Header AWIPS ID
Tsunami Message WEXX PAAQ TSUAT1

Table 2: Products Affected by Marine Zone Changes

Marine Weather Message WHUS74 KCRP MWWCRP
Special Marine Warning WHUS54 KCRP SMWCRP
Marine Weather Statement FZUS74 KCRP MWSCRP
Coastal Waters Forecast FZUS54 KCRP CWFCRP
Area Forecast Discussion FXUS64 KCRP AFDCRP
Hazardous Weather Outlook FLUS44 KCRP HWOCRP
Watch County Notification WWUS64 KCRP WCNCRP


Questions or Comments

If you have any questions or comments about this change, please contact:

Melissa Huffman

Warning Coordination Meteorologist

National Weather Service - Corpus Christi, TX

(361) 289-0959 x 223