Tropical Storm Yamaneko moved north of Wake Island on Sunday. At 4:00 p.m. EST on Sunday the center of Tropical Storm Yamaneko was located at latitude 23.4°N and longitude 166.0°E which put it about 245 miles (395 km) north of Wake Island. Yamaneko was moving toward the north 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.
Tropical Storm Yamaneko moved farther north of Wake Island on Sunday. The distribution of thunderstorms in Yamaneko was asymmetrical. Thunderstorms were occurring in bands in the far eastern part of Tropical Storm Yamaneko. Bands in the rest of Yamaneko’s circulation consisted primarily of showers and lower clouds. An upper level trough southeast of Japan was producing strong southwesterly winds that were blowing across the top of Tropical Storm Yamaneko. Those winds were causing strong vertical wind shear. The strong vertical wind shear was causing the upper part of Yamaneko’s circulation to tilt toward the northeast. The strong upper level winds were also blowing off the tops of thunderstorms that started to form near the center of Yamaneko and in the western part of the circulation.
Tropical Storm Yamaneko will move through an environment that will cause it to make a transition to an extratropical cyclone during the next 36 hours. Yamaneko will move over water where the Sea Surface Temperatures are colder than 26˚C. The upper level trough southeast of Japan will continue to cause strong vertical wind shear. A combination of cooler water and strong vertical wind shear will cause Tropical Storm Yamaneko to make a transition to an extratropical cyclone.
The upper level trough will steer Tropical Storm Yamaneko toward the north-northeast during the next 36 hours. On its anticipated track, Tropical Storm Yamaneko will pass far to the west of Midway Island in 24 hours.
Tropical Storm Banyan rapidly intensified into a typhoon on Saturday. At 5:00 p.m. EDT on Saturday the center of Typhoon Banyan was located at latitude 20.8°N and longitude 164.3°E which put it about 165 miles (265 km) west-northwest of Wake Island. Banyan was moving toward the north-northwest at 7 m.p.h. (11 km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 115 m.p.h. (185 km/h). The minimum surface pressure was 976 mb.
Banyan intensified rapidly from a tropical storm into a typhoon in less than 36 hours. Banyan is a small well organized typhoon. There is a small circular eye at the center of circulation. The eye is surrounded by a ring of strong thunderstorms. The strongest winds are occurring in that ring of storms. A primary band of thunderstorms wraps around the eastern and northern sides of the core of Typhoon Banyan. Other bands of showers and storms are revolving around the core of the typhoon. Banyan has a small circulation. Winds to typhoon force only extend out about 25 miles (40 km) from the center of circulation. Winds to tropical storm force only extend out about 100 miles (160 km) from the center.
Typhoon Banyan will continue to move through an environment that is favorable for intensification on Sunday. Banyan will move over water where the Sea Surface Temperature is near 30°C. The upper level winds are weak and there is little vertical wind shear. Typhoon Banyan will continue to intensify during the next 24 hours and it could become the equivalent of a major hurricane.
Banyan is moving around the western end of a subtropical ridge, which is steering the typhoon toward the north-northwest. Banyan is forecast to continue to move toward the north-northwest for another day or two. On its anticipated track Typhoon Banyan will move away from Wake Island and the weather should improve on Sunday.
Both Tropical Storms Kilo and Loke weakened on Saturday and were downgraded to tropical depression status. At 5:00 p.m. EDT on Saturday the center of Tropical Depression Kilo was located at latitude 14.2°N and longitude 159.4°W which put it about 500 miles (805 km) south-southwest of Honolulu, Hawaii. Kilo was moving toward the west-northwest at 15 m.p.h. (24 km/h). The maximum sustained wind speed was 30 m.p.h. (50 km/h) and there were wind gusts to 40 m.p.h. (65 m.p.h.). The minimum surface pressure was 1005 mb.
At 5:00 p.m. EDT on Saturday the center of Tropical Depression Loke was located at latitude 18.1°N and longitude 178.6°W which put it about 700 miles (1130 km) south of Midway Island. Loke was moving toward the northwest at 8 m.p.h. The maximum sustained wind speed was 35 m.p.h. (55 km/) and there were wind gusts to 45 m.p.h. (70 km/h). The minimum surface pressure was 1003 mb.
Kilo appeared to be affected by vertical wind shear for much of Saturday. A reconnaissance aircraft had a difficult time trying to find a surface circulation center and the spiral bands were not well developed. Upper level easterly winds appeared to be pushing the tops of thunderstorms west of the low level circulation and inhibiting the formation of a warm core in the upper levels. Recent satellite imagery suggests that more thunderstorms could be forming closer to the center of Kilo. The vertical wind shear is forecast to decrease and Kilo could strengthen during the next few days. A subtropical ridge is steering Kilo westward, but the ridge is expected to weaken and the steering currents could become weaker on Sunday. Eventually, an upper level trough approaching from the northwest is forecast to pull Kilo toward the northeast early next week.
Loke appears to be very well organized for a tropical depression. A primary rainband wraps around the western and southern side of the center of circulation and there appears to be about three quarters of an eyewall trying to form around the center. The thunderstorms in the band are generating upper level divergence. Loke is over warm Sea Surface Temperatures. However, an upper level trough northwest of Loke is generating some southwesterly winds that are creating some vertical wind shear and are inhibiting upper level divergence south of the center of circulation. That same upper level trough is expected to steer Loke toward the north-northeast during the next few days. On it anticipated track Loke could be near Midway Island in about 60 hours.
Two tropical storms formed over the Central Pacific Ocean on Friday. At 5:00 p.m. EDT on Friday the center of Tropical Storm Kilo was located at latitude 13.0°N and longitude 153.3°W which put it about 480 miles (770 km) south-southeast of Hilo, Hawaii. Kilo was moving toward the west-northwest at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 40 m.p.h. (65 km/h) and there were gusts to 50 m.p.h. (80 km/h). The minimum surface pressure was 1004 mb.
At 5:00 p.m. EDT on Friday the center of Tropical Storm Loke was located at latitude 16.4°N and longitude 177.2°W which put it about 815 miles (1310 km) south of Midway Island. Loke was moving toward the north at 6 m.p.h. (9 km/h). The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 55 m.p.h. (90 km/h). The minimum surface pressure was 1000 mb.
Tropical Storm Kilo is not very well organized at the present time. Strong easterly winds in the upper levels are blowing the tops off of the thunderstorms and the vertical wind shear is keeping Kilo from intensifying. If the shear decreases as some numerical models forecast, then Kilo could intensify. On the other hand, if the shear stays strong, then Kilo could weaken to a tropical depression. If Kilo intensifies as some models suggest, then it could be pushed toward the western Hawaiian Islands. However, if Kilo stays weaker, then winds lower in the atmosphere could steer more toward the west and keep it south of Hawaii.
Tropical Storm Loke is better organized, although most of the stronger thunderstorms are north of the center. An upper level trough northwest of Loke could be creating some southwesterly winds around the tropical storm. Although the vertical wind shear may be slowing the rate of intensification, Loke does appear to be getting stronger. The upper level trough is expected to steer Loke toward the north and it could approach Midway Island in four or five days. Loke could be a hurricane at that time.