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NOUS44 KHUN 241432  
PNSHUN  
ALZ001>010-016-TNZ076-096-097-250245-  
 
PUBLIC INFORMATION STATEMENT  
NATIONAL WEATHER SERVICE HUNTSVILLE AL  
932 AM CDT THU APR 24 2025  
 
TO: SUBSCRIBERS:  
-NOAA WEATHER WIRE SERVICE  
-EMERGENCY MANAGERS WEATHER INFORMATION NETWORK  
-NOAAPORT  
OTHER NWS PARTNERS AND NWS EMPLOYEES  
 
FROM: GREG SCHOOR, CHIEF  
MARINE, TROPICAL AND TSUNAMI SERVICES BRANCH  
 
SUBJECT: HURRICANE THREATS AND IMPACTS (HTI) MOSAIC TESTING ON  
APRIL 24, 2025 (BACKUP DATE: APRIL 29, 2025)  
 
THE NATIONAL WEATHER SERVICE (NWS) WEATHER FORECAST OFFICES (WFOS) IN  
HONOLULU, HAWAII, SAN JUAN, PUERTO RICO, AND ALL WFOS IN THE CONTIGUOUS  
UNITED STATES THAT CAN ISSUE TROPICAL STORM AND HURRICANE HAZARDS WILL  
COMMENCE WITH HURRICANE THREATS AND IMPACTS (HTI) THREAT GRID MOSAIC  
TESTING ON THURSDAY, APRIL 24, 2025. TESTING WILL BEGIN AT APPROXIMATELY  
1500 UTC. TEST ACTIVITIES WILL TAKE APPROXIMATELY 1 HOUR. HOWEVER, NWS  
DISSEMINATION SYSTEMS MAY TAKE UP TO AN HOUR AND A HALF TO PURGE ALL TEST  
DATA. ALL TEST DATA IS EXPECTED TO BE CLEARED BY 1730 UTC.  
 
IN THE EVENT THAT THE COMMENCEMENT DATE IS DECLARED A CRITICAL WEATHER DAY  
(CWD), AN ENHANCED CAUTION EVENT, OR OTHER EVENT IS OCCURRING OR IS  
ANTICIPATED TO OCCUR, THE TESTING WILL COMMENCE AT THE AFFECTED OFFICES ON  
APRIL 29, 2025.  
 
FOR THE TEST, HTI GRIDS WILL BE CREATED FOR HURRICANE WIND THREAT, FLOODING  
RAIN THREAT, TORNADO THREAT, AND STORM SURGE THREAT (WHERE APPLICABLE) AT  
EACH PARTICIPATING WFO. THOSE GRIDS ARE STITCHED TOGETHER INTO STORM-SCALE  
HTI GRAPHICS. THE HTI MOSAIC GRAPHICS ARE AVAILABLE IN KEYHOLE MARKUP  
LANGUAGE (KML) FORMAT ON THE FOLLOWING WEBPAGE:  
HTTPS://WWW.WEATHER.GOV/HTI  
 
THE MOSAICS ARE ALSO AVAILABLE THROUGH THE NATIONAL DIGITAL FORECAST  
DATABASE AND ON WEB PAGES HOSTED BY THE WEATHER FORECAST OFFICES (WFOS)  
AFFECTED BY TROPICAL CYCLONES. THESE WEBPAGES INCLUDE WFO TROPICAL WEBPAGES  
AND GRAPHICAL HAZARDOUS WEATHER OUTLOOK (GHWO) WEBPAGES.  
 
GHWO WEBPAGES USE THE FOLLOWING URL FORMAT, WHERE “XXX” SHOULD BE REPLACED  
WITH THE 3-LETTER IDENTIFIER FOR THE WFO OF INTEREST (NOTE THAT WFO  
HONOLULU DOES NOT HAVE A GHWO WEBPAGE):  
HTTPS://WWW.WEATHER.GOV/ERH/GHWO?WFO=XXX  
 
WFO 3-LETTER IDENTIFIERS AND THE RESPECTIVE NWS REGION THAT EACH WFO  
BELONGS TO IS LISTED AT THE FOLLOWING PAGE:  
HTTPS://WWW.WEATHER.GOV/PIMAR/CWABYWFO  
 
NWS EASTERN, SOUTHERN, AND WESTERN REGION WFO TROPICAL WEBPAGES USE THE  
FOLLOWING URL FORMAT, WHERE “XXX” SHOULD BE REPLACED WITH THE 3 LETTER  
IDENTIFIER FOR THE WFO OF INTEREST:  
 
NWS EASTERN REGION WFOS:  
HTTPS://WWW.WEATHER.GOV/XXX/TROPICAL#HTI  
 
NWS SOUTHERN REGION AND WESTERN REGION WFOS:  
HTTPS://WWW.WEATHER.GOV/SRH/TROPICAL?OFFICE=XXX#HTI  
 
THE TROPICAL WEBPAGE FOR WFO HONOLULU CAN BE FOUND AT:  
HTTPS://WWW.WEATHER.GOV/HFO/HTI  
 
USER INFORMATION ABOUT HTI CAN BE FOUND HERE:  
HTTPS://WWW.WEATHER.GOV/MEDIA/SRH/TROPICAL/HTI_EXPLANATION.PDF  
 
MORE SPECIFIC DETAILS ON HTI CAN BE FOUND IN THE PRODUCT DESCRIPTION  
DOCUMENT:  
HTTPS://WWW.WEATHER.GOV/MEDIA/SRH/TROPICAL/PDD_HTI.PDF  
 
PERIODIC SOFTWARE AND HARDWARE TESTING IN PREPARATION FOR TROPICAL CYCLONE  
EVENTS WILL CONTINUE DURING THE REMAINDER OF 2025.  
 
FOR MORE INFORMATION, PLEASE CONTACT:  
 
KATE GUILLET  
WARNING COORDINATION METEOROLOGIST  
NATIONAL WEATHER SERVICE OFFICE  
HUNTSVILLE, AL  
KATE.GUILLET@NOAA.GOV  
 
NATIONAL PUBLIC INFORMATION STATEMENTS ARE ONLINE AT:  
HTTPS://WWW.WEATHER.GOV/NOTIFICATION/  
 
NNNN  
 
 
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