On December 28, Tropical Depression 23W developed about to the west of the island of Palau. PAGASA also named the system as "Seniang". A few hours later, the system had rapidly organized and was considered as a tropical storm, with the name "Jangmi". By December 29, Jangmi made landfall over the town of Hinatuan in the province of Surigao del Sur and briefly reached its peak strength packing maximum winds of . The storm traversed the Caraga region, and exited the landmass of Mindanao as the system had slowly weakened. During the next day, Jangmi made landfall over Cebu and southern Negros, right before the JTWC downgraded it to a tropical depression. Both agencies made their final warning on Jangmi on January 1, 2015, as the 2015 Pacific typhoon season started.