Anatomy of a Disaster
Track map of Tropical Storm Washi. The points show the location of the storm at 6-hour intervals.
On December 12, 2011, a developing area of low pressure had persisted about 945 km south-southeast of Guam. Situated along the southern edge of a subtropical ridge, the system tracked steadily westward towards the Philippines. The following day, the system was classified as a tropical depression. Maintaining a westward track, the depression was forecast to intensify slowly over the following three days. By December 14, convection redeveloped over the low and the system has attained tropical storm status - Tropical Storm Washi (international designation).