 An hour prior, the Joint Typhoon Warning Center (JTWC) initiated advisories on Tropical Cyclone 11S, while the storm was located about 215 km (130 mi) south-southeast of Christmas Island.After becoming a named storm, Leon turned more to the west-southwest, due to a trough weakening the ridge to the south.The storm developed increased convective banding, aided by decreasing wind shear, and quickly intensified.