Two unusual subtropical storms are fading away in the Atlantic Ocean, with one in the North Atlantic and the other in the South Atlantic. The North Atlantic system was named “Andrea” by the National Hurricane Center on Monday while the South Atlantic system was named “Jaguar” by the Brazilian Navy on Monday too.
According to the most recent update from the National Hurricane Center (NHC), Andrea, now weakened to subtropical depression status, was located near latitude 30.8 North and longitude 69.2 West. The subtropical depression is moving toward the north near 8 mph and a turn toward the northeast and east is expected tonight. Maximum sustained winds have decreased to near 35 mph with higher gusts. Continued weakening is forecast by the NHC and Andrea is expected to degenerate into a remnant low by this evening. The estimated minimum central pressure is 1009 mb or 29.80 inches. Andrea failed to gain strength because of the current weather pattern over the Atlantic; an approaching frontal system over the ocean will absorb its remnants; beforehand, the flow around it wasn’t favorable for any development on its own. Andrea was somewhat unusual because it formed before the start of the Atlantic Hurricane Season which begins on June 1. While not an extremely common occurrence, systems do form before the June 1 seasonal start date from time to time.
An even more rare system developed off the coast of Espírito Santo and Rio de Janeiro yesterday. On Sunday, an area of low atmospheric pressure evolved into a subtropical depression. That depression intensified to subtropical storm and was classified as such by the Brazilian Navy on Monday, being named Jaguar in the process. Subtropical and tropical storms are extremely rare in the South Atlantic and Jaguar makes it even more rare by being the second of the year. In March, Iba formed. The Brazilian Navy says the “formation of subtropical storms in the South Atlantic in May is a rare occurrence, because at this time sea water is not warmer to sustain this kind of instability.” But this year, the Brazilian coast has been anomalously warm, helping fuel strong areas of instability especially in the coast of the Southeast since early summer. Because of their rarity, storms are named from a fixed list in South America. Should new storms form in the basin, the next two would be named Kamby and Mani regardless of when they form. Like Andrea, Jaguar is encountering an environment that is hostile for growth. As such, its remnants are expected to fade as it continues to move away from the South American coast.