219  
NOUS42 KCHS 071948  
PNSCHS  
GAZ087-088-099>101-114>119-137>141-SCZ040-042>045-047>052-081800-  
 
PUBLIC INFORMATION STATEMENT  
NATIONAL WEATHER SERVICE CHARLESTON SC  
345 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:  
 
STEVE ROWLEY  
SCIENCE AND OPERATIONS OFFICER  
NATIONAL WEATHER SERVICE OFFICE  
CHARLESTON SC 29406  
NWS.CHARLESTONSC@NOAA.GOV  
 
843-744-1732  
 
NATIONAL PUBLIC INFORMATION STATEMENTS ARE ONLINE AT:  
HTTPS://WWW.WEATHER.GOV/NOTIFICATION/  
 

 
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SC Page
The Nexlab GA Page Main Text Page