Tropical Storm Krosa moved toward Japan on Sunday after stalling south of Iwo To for several days. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Krosa was located at latitude 24.7°N and longitude 137.5°E which put it about 255 miles (410 km) west of Iwo To. Krosa was moving toward the west-northwest at 9 m.p.h. (15 km/h). The maximum sustained wind speed was 70 m.p.h. (110 km/h) and there were wind gusts to 85 m.p.h. (135 km/h). The minimum surface pressure was 965 mb.
Tropical Storm Krosa mixed significant amounts of cooler water to the surface during the days when it was nearly stationary south of Iwo To. The cooler ware contained less energy and the atmosphere became more stable. Thunderstorms around the core of the circulation dissipated and the storms in many of the rainbands also weakened. Some thunderstorms persisted in outer rainbands. Even though the maximum wind speed decreased, the size of the circulation increased. Winds to tropical storm force extended out about 280 miles (455 km) from the center of circulation.
Tropical Storm Krosa will move through an environment favorable for intensification during the next several days. Krosa will move over water where the Sea Surface Temperature is near 29°C after it gets away from the cooler water mixed to the surface. It will move through a region where there will not be a lot of vertical wind shear. Tropical Storm Krosa will intensify slowly at first because it lacks a strong inner core. If more thunderstorms develop near the center of circulation, then Krosa could strengthen more quickly. It is possible that thunderstorms do not form at the center of circulation and if that happens, Krosa could develop into a typhoon with a very large eye at the center.
Tropical Storm Krosa will move around the western end of a subtropical ridge over the Western North Pacific Ocean. The ridge will steer Krosa toward the northwest during the next two or three days. On its anticipated track Tropical Storm Krosa could approach southwestern Japan within 72 hours. Krosa is likely to be a large typhoon by that time.
Elsewhere of over the Western North Pacific Ocean, Tropical Storm Lekima continue to bring wind and rain to parts of northeastern China. At 11:00 p.m. EDT on Sunday the center of Tropical Storm Lekima was located at latitude 37.8°N and longitude 119.6°E which put it about 150 miles (240 km) south-southeast of Tangshan, China. Lekima was moving toward the north- northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were wind gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 985 mb.