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ARZ004>008-014>017-024-025-031>034-039-042>047-052>057-062>069-
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237-238-240-241-313-340-341-241600-

Public Information Statement
National Weather Service Little Rock AR
705 AM CDT Thu Apr 24 2025


o:        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:

Chris Buonanno
Science and Operations Officer
National Weather Service Office
Little Rock AR
christopher.buonanno@noaa.gov


National Public Information Statements are online at:
https://www.weather.gov/notification/



$$