Public Information Statement
Issued by NWS San Juan, PR

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NOCA42 TJSJ 111353

Public Information Statement
National Weather Service San Juan PR
953 AM AST Thu Apr 11 2024

o:        Subscribers:
           -NOAA Weather Wire Service
           -Emergency Managers Weather Information Network
           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 11, 2024 and April 25, 2024

The National Weather Service (NWS) Weather Forecast Offices (WFOs) in Honolulu,
San Juan, San Diego, and Los Angeles along with WFOs in the NWS Southern
Region west of the Mississippi River will commence with Hurricane Threats
and Impacts (HTI) threat grid mosaic testing on Thursday, April 11. A second
test that will include WFOs east of the Mississippi River is planned for
April 25.

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, Storm Surge
Threat, Flooding Rain Threat, and Tornado Threat 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:

The mosaics are also available through the National Digital Forecast Database
and on web pages hosted by the Weather Forecast Offices (WFOs) affected by
the tropical cyclone. These webpages use the following URL format, where
“wfo” should be replaced with the 3 digit identifier for the WFO of

NWS Southern and Western Region WFOs:

WFO Honolulu:

More details on HTI can be found in the Product Description Document:

Periodic software and hardware testing in preparation for tropical cyclone events
will continue during the remainder of 2024.

For more information, please contact:

  Ernesto Rodriguez
  National Weather Service Office
  San Juan PR, 00926

National Public Information Statements are online at:


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