652
NOUS41 KNHC 151352
PNSNHC

Public Information Statement
NWS National Hurricane Center Miami FL
1000 AM EDT Thu May 15 2025

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

From:      Daniel Brown, Branch Chief
           Hurricane Specialist Unit
           National Hurricane Center

Subject:   Stepped Frequency Microwave Radiometer (SFMR) Data
           from NOAA Aircraft Unavailable for the Start of the
           2025 Hurricane Season Due to Data Quality Concerns

The Stepped Frequency Microwave Radiometer (SFMR) instrument on
NOAA`s P-3 hurricane hunter aircraft measures surface brightness
temperature and applies an algorithm to generate a real-time measure
of surface wind speed and rain rate in tropical cyclones and
disturbances.

During the first half of the 2024 hurricane season, NOAA scientists
determined the SFMR data integrity on the NOAA aircraft fleet was
degraded and deemed to be unreliable. To ensure data quality, NOAA
discontinued real-time transmission of the SFMR data during the
final months of the 2024 hurricane season.

NOAA scientists continue to conduct data validation and calibration
to determine the issue and restore SFMR data quality. Until this
work is complete, SFMR data from NOAA aircraft will not be
transmitted in real time for operational use at NOAA`s National
Hurricane Center and Central Pacific Hurricane Center, or for use in
data assimilation, but it will still be collected for research and
continued calibration efforts.

When available, SFMR data from NOAA Hurricane Hunter aircraft are
found under the following AWIPS Product Identifiers (PIL) and World
Meteorological Organization (WMO) Identifiers (ID):

Text Product                         AWIPS PIL        WMO ID
------------                         ---------        ------
High Density Observations (NOAA/AOC)   AHONT1       URNT15 KWBC
Atlantic Basin

High Density Observations (NOAA/AOC)   AHOPN1       URPN15 KWBC
Eastern and Central North Pacific Basins

An update on the availability of real-time SFMR data on NOAA
Hurricane Hunter aircraft will be provided as new information on the
data reliability and calibration becomes available.

For more information, please contact:

     Daniel Brown
     Branch Chief
     Hurricane Specialist Unit
     NOAA/NWS National Hurricane Center
     Daniel.P.Brown@noaa.gov