The system that would later become Tropical Storm Jerry started as a non-tropical low pressure area over the central Atlantic Ocean on September 21. The system moved in a shaky path over the north-central Atlantic over the next two days. It slowly developed deeper convection and became more organized. On September 22, the system had become organized enough that the National Hurricane Center mentioned a possible tropical or subtropical development in the area. Late that evening, it had been determined that a subtropical depression had formed, as a warm core had developed but the system was still involved with an upper-level low and had its strongest winds well removed from the center. Early on September 23, both satellite estimates and QuikScat data determined that the depression had strengthened into Subtropical Storm Jerry, despite the lack of a well-defined inner core. The storm slowly acquired tropical characteristics including a better-defined warm core, and became fully tropical that evening as a weak and sheared tropical storm with 40 mph (65 km/h) winds over a small radius.