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Public Information Statement
National Weather Service Honolulu HI
745 AM HST Wed Apr 29 2026


To:        Subscribers:
           -NOAA Weather Wire Service
           -Emergency Managers Weather Information Network
           -NOAAPort
           Other NWS Partners and NWS Employees

From:      Jamie Rhome, Deputy Director
           National Hurricane Center

Subject:   Tropical Collaboration Testing April 28 and 29
(Backup Date April 30 and May 19-21)

The NWS National Hurricane Center (NHC) and select Weather Forecast
Offices (WFOs) in the NWS Eastern, Southern, and Pacific Regions
will perform internal tropical collaboration testing April 28 and
29, 2026. If testing is unable to be conducted these days, testing
will instead be conducted April 30 or May 19-21, 2026.

WFOs participating in the test include the following:
- Charleston, SC (CHS)
- Honolulu, HI (HFO)
- Lake Charles, LA (LCH)
- Mobile, AL (MOB)
- Morehead City, NC (MHX)
- New Orleans, LA (LIX)
- Wakefield, VA (AKQ)
- Wilmington, NC (ILM)

This internal testing will begin daily at approximately 1400 UTC
and terminate at 2000 UTC.

The testing will include the exchange of tropical watches and
warnings between NHC and the testing WFOs, generation of the
National Tropical Cyclone Watch/Warning (TCV) product, generation
of P-surge data, and the addition of tropical cyclone information
into National Digital Forecast Database (NDFD) elements.

Internal TCV test products and NDFD elements are not intended to
be released externally through NWS dissemination and
communication systems. Any TCV products that are inadvertently
released during the testing period are solely for testing purposes
and do not represent current or forecast weather conditions.

The text product affected by collaboration testing is the National
Tropical Cyclone Watch/Warning (TCV) product issued under the
following AWIPS Product Identifiers (PIL) and World Meteorological
Organization (WMO) Identifiers (ID):

TCV Product                    AWIPS PIL   WMO ID
------------                   ---------   -------
Atlantic National TCV          TCVAT/1-5/  WTNT/81-85/ KNHC

Note: A National TCV is not issued for the Central Pacific/HFO.

The national TCV product contains a summary of collaborated wind
and/or storm surge watches and warnings, depicted by NWS-defined
geographic zones.

In addition, the following NDFD elements will be created for this test:
     - Tropical cyclone wind probabilities (incremental and
       cumulative) for 34 kt, 50 kt, and 64 kt
     - Hazard grid (including tropical storm, hurricane, and
       storm surge hazards)
     - Wind and wind gust grids with tropical cyclone strength
       winds

P-surge guidance will be run during the test and the test data will
be available publicly at the following URL:
https://slosh.nws.noaa.gov/psurge/

The NWS will continue periodic internal tropical software testing
during the remainder of 2026.

For more information, please contact:

Chris Brenchley
Meteorologist in Charge
National Weather Service Office Honolulu, Hawaii
christopher.brenchley@noaa.gov

National Public Information Statements are online at:

https://www.weather.gov/notification/

NNNN

$$