Super Typhoon Nanmadol became one of the strongest typhoons to threaten Japan since records began in 1951. Nanmadol began as a tropical disturbance, basically an area of active thunderstorms, on September 11th southeast of Iwo Jima about midway between Tokyo and Guam. After moving to the southwest for 2 days, this disturbance became better organized and formed into a depression on the 13th. The system then made a counterclockwise loop, moving first back to the northeast before turning back again towards the west. Over this time, the system slowly intensified, becoming Tropical Storm Nanmadol
