by Eric Berger
Ars Technica / 2017-03-25 11:07
Enlarge / The European model shows the formation of a subtropical cyclone next Tuesday in the Atlantic Ocean. (credit: Weather Bell)
Just one hurricane has ever formed in the northern Atlantic Ocean, Caribbean Sea, or the Gulf of Mexico in the month of March—a time when the oceans are still cold from the winter months in the northern hemisphere. This occurred in 1908 with an unnamed hurricane that, according to the Atlantic Hurricane database, reached sustained winds of 100mph and caused damage in the Caribbean islands.
As the 1908 cyclone formed long before the National Hurricane Center existed, there has never been a "named" storm in March. That could change next week, as an area of low pressure may develop several hundred miles to the east of Florida, in the Atlantic Ocean. This storm system is unlikely to be a major threat to landmasses, with the possible exception of Bermuda. Due to the rarity of March cyclones, however, it would garner significant attention.
Any cyclone that forms next week would almost certainly be classified as a "subtropical storm" (the Miami-based National Hurricane Center began naming subtropical storms, in addition to tropical storms, in 2002). It would originate from a mass of cold air that recently moved off of the United States, eastward, into the subtropical area of the Atlantic Ocean. Unlike "tropical" storms, subtropical storms have cold air at their centers and generate energy from the interaction of cold and warm air masses. (By contrast, a tropical cyclone derives energy from latent heat, as water vapor evaporates from the ocean’s surface and condenses into liquid water).