According to the National Hurricane Center, the phenomenon formed about 1,600 kilometers southwest of the Azores Islands and had maximum sustained winds of 85 kilometers per hour.
Theta became Storm number 29 named after the Atlantic hurricane season that has formed in the open sea, international media reported Monday night.
The National Hurricane Center of the United States (NHC, for its acronym in English), indicated that Storm Subtropical Theta has emerged in the Northwest Atlantic, and that, at the moment, did not pose an immediate threat to the mainland.
The NHC said in a statement issued at 10 p.m. Monday that the phenomenon had formed about 1,600 kilometers (995 miles) southwest of the Azores Islands and had maximum sustained winds of 85 km / h (50 mph).
He added that there were no warnings in effect, and that the storm was moving east at about 15 mph (24 km / h).
Theta is forecast to continue in an east-northeast direction in the coming days, and forecasters believe it could strengthen slightly in the next 12 to 24 hours.
Theta, a letter in the Greek alphabet being used for the first time, broke the previous record of 28 named storms in a season established in 2005, the National Hurricane Center noted.
Regarding tropical storm Eta, this was moving away this Monday from the Florida Keys and the south of this peninsula, while it will remain over the southeast of the Gulf of Mexico until Wednesday.