NOUS41 KNHC 111500
Public Information Statement
NWS National Hurricane Center Miami FL
1100 AM EDT Thu May 11 2023
...NHC Determines That a Subtropical Storm Formed in the Atlantic
Basin in Mid-January 2023...
Through the course of typical re-assessment of weather systems in
the National Hurricane Center's (NHC) area of responsibility, NHC
hurricane specialists have determined that an area of low pressure
that formed off the northeastern coast of the United States in
mid-January should be designated as a subtropical storm. Specific
information on the justification for the subtropical storm
designation, as well as the system's synoptic history and impacts,
will be available in a Tropical Cyclone Report, which will likely be
issued during the next couple of months.
This subtropical storm is being numbered as the first cyclone of
2023 in the Atlantic basin and will be given AL012023 as its system
ID. As a result, the next system that forms in 2023 in the Atlantic
basin will be designated as AL022023, and advisories will be issued
in AWIPS bin 2 (e.g., Public Advisories will be issued under AWIPS
header TCPAT2 and WMO header WTNT22 KNHC). If the system begins as
a tropical depression, then it would be given the designation
'TROPICAL DEPRESSION TWO', and if it becomes a tropical storm, it
would be given the name 'ARLENE'.
National Weather Service policy (through NWS Instruction 10-607,
Section 1) allows for marginal subtropical systems to be handled in
real-time as non-tropical gale or storm events in NWS High Seas
Forecast products. This was the procedure followed for the unnamed
subtropical storm in mid-January. However, the lack of real-time
issuance of advisories does not preclude NHC from retroactively
designating these systems as a subtropical cyclones in
post-analysis, if necessary.
Hurricane Specialist Unit