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National Weather Service Office in Slidell, Louisiana Announces

Forecast Zone Changes for Coastal Mississippi

WHY: Current zone configurations result in an over-alerting of storm surge warnings through the Wireless Emergency Alert System. The proposed subdivisions are part of an ongoing effort to allow for more precise alerting of storm surge threats and other coastal flooding threats. The new zones will roughly account for the surge threats posed by most hurricanes.

WHERE: The following counties will be newly subdivided: Hancock, Harrison, and Jackson based on coordination with local officials.

Hancock County (Mississippi): The county is currently a single zone. The zone will be subdivided into two zones: Northern Hancock County and Southern Hancock County. The dividing line between the new zones will extend from where Old US Hwy 11 intersects the western county border to near where Bayou Bacon and the Adgreen Branch join together to near where Kiln-Delisle Road intersects the western county border.

A partial list of locations included in the two newly divided zones follows.

Northern Hancock County: Necaisse, Sellers

Southern Hancock County: Pearlingon, Waveland, Bay St. Louis, Diamondhead, Kiln

(see maps below)

Harrison County (Mississippi): The county is currently a single zone. The zone will be subdivided into two zones: Northern Harrison County and Southern Harrison County. The dividing line between the new zones will extend from near where Kiln-Delisle Road intersects the western county border to near where the Bayou Costapia intersects the eastern county border.

A partial list of locations included in the two newly divided zones follows.

Northern Harrison County: Lyman, Saucier

Southern Harrison County: Pass Christian, Long Beach, Gulfport, Biloxi

(see maps below)

Jackson County (Mississippi): The county is currently a single zone. The zone will be subdivided into two zones: Northern Jackson County and Southern Jackson County. The dividing line between the new zones will extend from near where the Tchoutacabouffa River intersects the western county border to the intersection of Hwy 57 and McGregor Rd to where Forts Lake Road intersects the eastern county border.

A partial list of locations included in the two newly divided zones follows.

Northern Jackson County: Wade, Vancleave, Esctawpa

Southern Jackson County: Ocean Springs, Gautier, Moss Point, Pascagoula

(see maps below)

WHEN: The zone implementation will occur during the day on Wednesday, March 8, 2023. If active weather prevents the change from taking place, the backup date is Thursday, March 9, 2023.

IS THIS NORMAL?

YES! The NWS frequently reconfigures forecast zones to provide better service to its partners and the public. Locally, the most recent zone reconfiguration occurred in 2021 when St. Tammany, Tangipahoa, Livingston, Jefferson, St. Bernard, and Plaquemines Parishes were reconfigured to better convey storm surge and coastal flood threats. In general, zone reconfigurations have shown to provide increased forecast detail, especially when dealing with winter weather and tropical conditions.

Which NWS products will be affected?

The table below lists the affected products by AWIPS ID and WMO Heading.

PRODUCT NAME AWIPS ID WMO HEADING

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NON PRECIPITATION WARNING/WATCH/ADVISORY NPWLIX WWUS74 KLIX

WINTER WEATHER MESSAGE WSWLIX WWUS44 KLIX

FLOOD WATCH FFALIX WGUS64 KLIX

AREA FORECAST MATRICES AFMLIX FOUS54 KLIX

TABULAR STATE FORECAST SFTLIX FPUS64 KLIX

SHORT TERM FORECAST NOWLIX FPUS74 KLIX

SPECIAL WEATHER STATEMENT SPSLIX WWUS84 KLIX

ZONE FORECAST ZFPLIX FPUS54 KLIX