Typhoon Lupit, known in the Philippines as Typhoon Yoyoy, destroyed the food supply in several small islands in Yap State in the Federated States of Micronesia (FSM). It formed on November 18, 2003, from the monsoon trough to the west of the Marshall Islands. Early in its duration, it moved generally to the west or west-southwest. On November 21, the depression intensified into Tropical Storm Lupit, the 21st storm named by the Japan Meteorological Agency of the 2003 Pacific typhoon season. Two days later, it strengthened into a typhoon and developed an eye. Lupit later began a prolonged movement to the northwest, during which it passed near several islands in Yap State. The typhoon reached peak intensity on November 26, with peak 10-minute sustained winds of 185 km/h (115 mph). It later weakened due to increasing wind shear and drier air, and after recurving to the northeast, Lupit became extratropical south of Japan on December 2.

The 2003 Pacific typhoon season was a slightly below average yearlong period of tropical cyclogenesis exhibiting the development of 45 tropical depressions, of which 21 became named storms; of those, 14 became typhoons. Though every month with the exception of February and March featured tropical activity, most storms developed from May through October. During the season, tropical cyclones affected the Philippines, Japan, China, the Korean Peninsula, Indochina, and various islands in the western Pacific.