Responsibilities and timeliness for aircraft reconnaissance and surveillance data
Misunderstandings exist about how NOAA's National Hurricane Center (NHC) obtains aircraft reconnaissance and surveillance
data and how those data are disseminated. Some have concluded incorrectly
that NOAA's National Weather Service (NWS) delays release of some data. We
expect the information below to clarify these issues.
- All NOAA G-IV and P-3 aircraft data except "Vortex Messages" are
transmitted from the aircraft automatically and immediately through National
Weather Service (NWS) dissemination systems to reach users.
- Remaining aircraft data (including "Vortex Messages" from the U.S. Air
Force C-130s and NOAA P-3s) go through a quality control (QC) process by the
aircrew and by the U.S. Air Force unit--the Chief, Aerial Reconnaissance
Coordination All Hurricanes (CARCAH)-- collocated with the NHC. CARCAH, not
the NWS/NHC, disseminates these products after the QC process is
- Preliminary reconnaissance data are often shared by CARCAH with the
collocated operational hurricane forecaster before CARCAH completes the QC
process. NHC products and/or media interviews sometimes reflect this
preliminary data up to a few minutes before the QC process is complete and
CARCAH generates and disseminates its Vortex Message product.
- The time stamp on the CARCAH Vortex Message product from the C-130s is
actually the time the crew on those aircraft locate the center of the
tropical cyclone. It can take up to 20 minutes for the crew to complete
their data analysis process and for the information to make its way to
CARCAH and the NHC facility from the aircraft. More time is required for
data QC, product generation, and dissemination. This is the reason
customers may receive the product 30 minutes, give or take, after the vortex
message time stamp, and this could be a source of the misunderstanding.
In short, there is no intentional delay in releasing hurricane
reconnaissance data by NOAA or by the Air Force.
Note: Once the Air Force Reserves switch from using the older C-130H
models to flying the newer C-130J models, a software change is expected to
enable CARCAH to time stamp the product with the actual time the Vortex
Message is generated, rather than a time that precedes completion of the
data gathering, analysis, QC, and product generation process.