When the storm became Tropical Depression One on May 28 , it was the third time since 1851 that an Atlantic tropical cyclone formed before June 1 , the official start of an Atlantic hurricane season . The depression followed Subtropical Storm Andrea of May 2007 and Tropical Storm Arthur of May 2008 . When Tropical Depression One formed on May 28 , it marked the third time since 1851 , when reliable records in the Atlantic basin began , that a pre-season cyclone developed in three consecutive years , following Subtropical Storm Andrea which formed in May of 2007 and Tropical Storm Arthur in May of 2008 .