Tropical Storm Yamaneko formed over the Western North Pacific Ocean northwest of Wake Island on Saturday afternoon. At 4:00 p.m. EST on Saturday the center of Tropical Storm Yamaneko was located at latitude 22.0°N and longitude 165.7°E which put it about 180 miles (295 km) north-northwest of Wake Island. Yamaneko was moving toward the north-northeast at 7 m.p.h. (11 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 1000 mb.
An area of low pressure over the Western North Pacific Ocean northwest of Wake Island strengthened on Saturday afternoon and the Japan Meteorological Agency designated the system as Tropical Storm Yamaneko. Thunderstorms near the center of circulation generated upper level divergence that pumped mass away to the east of the tropical storm. The inner end of a rainband wrapped around the northern and western side of the center of Yamaneko’s circulation. Other bands of thunderstorms were in the eastern half of Tropical Storm Yamaneko. Many of the bands in the western side of Yamaneko consisted primarily of showers and lower clouds. Winds to tropical storm force extended out 130 miles (210 km) in the eastern side of Tropical Storm Yamaneko. The winds in the western side of Yamaneko were blowing at less than tropical storm force.
Tropical Storm Yamaneko will move through an environment somewhat favorable for intensification during the next 24 hours. Yamaneko will move over water where the Sea Surface Temperatures are near 27˚C. An upper level trough southeast of Japan will produce southwesterly winds that will blow toward the top of Yamaneko’s circulation. Those winds will cause some vertical wind shear. The wind shear will inhibit intensification, but the shear will not be enough to prevent Yamaneko from getting a little stronger. Tropical Storm Yamaneko is likely to intensify gradually during the next 24 hours.
The upper level trough southeast of Japan will steer Tropical Storm Yamaneko toward the north during the next 24 hours. On its anticipated track, Tropical Storm Yamaneko will move farther away from Wake Island.