It was the 19th tropical storm and 12th typhoon of the 1979 Pacific typhoon season . The typhoon formed out of a disturbance in a monsoon trough on October 4 near Pohnpei . The nineteenth tropical storm and twelfth typhoon of the 1979 Pacific typhoon season , Tip developed out of a disturbance in the monsoon trough on October 4 near Pohnpei .