Subtropical storm formed in January, first storm of the 2023 Atlantic hurricane season

WEST PALM BEACH, Fla. (WPEC) — The National Hurricane Center released a statement on Thursday that the first storm of the 2023 Atlantic hurricane season formed in mid-January.

In the statement, the NHC said that a low-pressure system that formed off the northeast coast of the U.S. in mid-January should have been designated as a subtropical storm. Although it was a subtropical storm, it will not take a name, but it is technically the first storm.

Any storm that forms from this point on will be designated as the second storm of the season. This means that if a tropical depression forms, then it will be called Tropical Depression Two. If a tropical storm or hurricane forms, it will take the first name of the season Arlene.

Though uncommon, January cyclones aren't unheard of. Since 1851, there have been six documented January storms in the Atlantic Basin, including two hurricanes, Alex in 2016 and Alice in 1955. Hurricane Alice is the only known Atlantic hurricane to span two calendar years.

What is rare is for a storm to form this north in the Atlantic during winter months. The unnamed January storm was able to maintain its convection and core thanks to its movement over the warm Gulf Stream.

The NHC said that 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.

They also said National Weather Service policy 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 subtropical cyclones in post-analysis, if necessary.