Subtropical storm developed over Atlantic in January, NHC says

The first subtropical system of 2023 is in the books, and it took shape months before hurricane season at a time when most people were worried about when the next snowstorm would strike.

On Thursday, the National Hurricane Center said that after forecasters performed a reassessment of previous weather patterns, it was determined that a system over the Atlantic Ocean in mid-January briefly reached subtropical storm status.

A subtropical storm is a system that has some tropical characteristics but has cold air in its core rather than warm air.

"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," the NHC said.

Details about the storm, including maximum wind speed, were not given but will be provided in future updates.

A subtropical storm swirls off the east coast of the United States on Jan. 16. Image courtesy of NASA Worldview

Satellite imagery from Jan. 16 showed the subtropical storm off the coast of the eastern United States with the appearance of a small eye in the heart of the system.

Despite being reclassified as a subtropical storm, the January system was not given a name.

The first named storm of the 2023 Atlantic hurricane season will be known as Arlene.

While it is rare, tropical storms and hurricanes can develop outside the traditional Atlantic hurricane season, which runs from June 1 through Nov. 30.

The last time a tropical system formed in January was in 2016, when Hurricane Alex formed over the eastern Atlantic Ocean. January hurricanes were also observed in the Atlantic basin in 1954 and 1938.