 Forming as a tropical disturbance near the International Dateline on October 29 , the system moved westward at low latitude eventually organizing into a tropical depression on November 3 south of Guam . The system moved north of due west across the central Philippines and emerged into the South China sea before strengthening into a tropical storm on November 9 . Herbert moved westward , making landfall in Vietnam on November 11 before dissipating in Laos on November 12 . 
