 On October 5 , an operationally unnamed subtropical storm which had gone unnoticed by the NHC was absorbed by a temperate frontal low , which was moving to the southeast over the Azores . The low pressure system gained a more concentrated circulation and lost its frontal structure after absorbing the subtropical storm . The developing system became a subtropical storm itself early on October 8 , 580 miles ( 930 km ) southeast of Lajes in the Azores . However , the NHC decided not to name the system Vince at the time , because the water temperature was too low for normal development for a tropical cyclone . The storm gradually gained the tropical characteristics of symmetry and a warm inner core and became a tropical storm the next day . Its transformation to a tropical system occurred over water cooler than 24 ° C ( 75 ° F ) , much colder than the 26 @.@ 5 ° C ( 80 ° F ) usually required for tropical development . 
