Similar to the formation of Tropical Storm Iris, Tropical Storm Joan originated from a tropical disturbance over the western South China Sea on November 5. Tracking eastward, the system quickly organized and was immediately declared a tropical storm on November 6. Early the next day, a reconnaissance plane recorded a pressure of 1000 mbar (hPa), the lowest in relation to Joan; however, this was measured while the system was a minimal tropical storm. Continued development took place over the following day as a well-defined wall cloud developed within the system. Joan attained typhoon intensity during the afternoon of November 8 and reached its peak intensity with winds of 130 km/h (80 mph) shortly thereafter. Tropical Storm Joan made landfall in nearly the same location as Typhoon Iris in central Vietnam before rapidly weakening over land. The system eventually weakened to a tropical depression on November 9 before dissipating over Laos.