571  
NOUS42 KMLB 071903  
PNSMLB  
 
PUBLIC INFORMATION STATEMENT  
NATIONAL WEATHER SERVICE MELBOURNE FL  
303 PM EDT WED APR 7 2021  
 
TO: SUBSCRIBERS:  
-NOAA WEATHER WIRE SERVICE  
-EMERGENCY MANAGERS WEATHER INFORMATION NETWORK  
-NOAAPORT  
OTHER NWS PARTNERS AND NWS EMPLOYEES  
 
FROM: ALLISON ALLEN, CHIEF  
MARINE, TROPICAL AND TSUNAMI SERVICES BRANCH  
 
SUBJECT: HURRICANE THREATS AND IMPACTS (HTI) MOSAIC TESTING ON  
APRIL 8, 2021 (BACKUP DATE: APRIL 22, 2021)  
 
THE NWS WEATHER FORECAST OFFICE (WFO) IN HONOLULU AND WFOS IN  
THE NWS SOUTHERN REGION AND IN THE NWS EASTERN REGION WILL  
COMMENCE WITH HURRICANE THREATS AND IMPACTS (HTI) THREAT GRID  
MOSAIC TESTING ON THURSDAY, APRIL 8. THURSDAY, APRIL 22 HAS  
BEEN DESIGNATED AS THE BACKUP TEST DATE IN THE EVENT THAT  
TESTING CANNOT BE CONDUCTED ON APRIL 8.  
 
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.  
 
FOR THE TEST, HTI GRIDS WILL BE CREATED FOR HURRICANE WIND  
THREAT, HURRICANE STORM SURGE THREAT, HURRICANE FLOODING RAIN  
THREAT, AND HURRICANE TORNADO THREAT. THESE GRIDS ARE SENT TO  
THE NATIONAL DIGITAL FORECAST DATABASE (NDFD) AND CAN BE SEEN ON  
THE NDFD WEB VIEWER AT:  
HTTPS://DIGITAL.WEATHER.GOV  
 
THE PRODUCT DESCRIPTION DOCUMENT FOR THESE THREAT GRIDS CAN BE  
FOUND HERE:  
HTTPS://WWW.WEATHER.GOV/MEDIA/SRH/TROPICAL/PDD_HTI.PDF  
 
HTI GRIDS ARE CREATED BY WFOS FOR THEIR COUNTY WARNING AREA AND  
MOSAICKED TOGETHER TO FORM A MORE GEOGRAPHICALLY CONSISTENT  
DEPICTION OF THE THREAT POSED BY HURRICANE HAZARDS. THE HTI MOSAICS  
CAN BE FOUND IN KML FORMAT AT:  
HTTPS://WEATHER.GOV/HTI  
 
WHEN POPULATED HTI GRIDS ARE POSTED, THEY ALSO CAN BE FOUND ON THE  
WFO TROPICAL WEB PORTAL PAGE LINKED BELOW UNDER THE "THREATS AND  
IMPACTS" TAB:  
HTTPS://WWW.WEATHER.GOV/SRH/TROPICAL  
 
PERIODIC SOFTWARE AND HARDWARE TESTING IN PREPARATION FOR  
TROPICAL CYCLONE EVENTS WILL CONTINUE DURING THE REMAINDER  
OF 2021.  
 
FOR MORE INFORMATION, PLEASE CONTACT:  
 
MATTHEW VOLKMER  
SCIENCE AND OPERATIONS OFFICER  
NATIONAL WEATHER SERVICE OFFICE  
MELBOURNE, FL 32935  
MATTHEW.VOLKMER@NOAA.GOV  
321-255-0212  
 
NATIONAL PUBLIC INFORMATION STATEMENTS ARE ONLINE AT:  
HTTPS://WWW.WEATHER.GOV/NOTIFICATION/  
 

 
 
RODRIGUEZ  
 
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