On 5 October, 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 the 8th of October 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 , much colder than the usually required for tropical development.