Hurricane Barbara started to weaken on Wednesday when it moved over cooler water well to the east of Hawaii. At 5:00 p.m. EDT on Wednesday the center of Hurricane Barbara was located at latitude 14.3°N and longitude 127.5°W which put it about 1860 miles (2990 km) east of Hilo, Hawaii. Barbara was moving toward the west-northwest at 12 m.p.h. (19 km/h). The maximum sustained wind speed was 140 m.p.h. (220 km/h) and there were wind gusts to 170 m.p.h. (275 km/h). The minimum surface pressure was 941 mb.
The circulation around Hurricane Barbara remained very well organized. There was a circular eye at the center of circulation. The eye was surrounded by a ring of strong thunderstorms and the strongest winds were occurring in that ring of storms. Several bands of showers and thunderstorms were revolving around the core of Hurricane Barbara. Storms near the core of the circulation were generating strong upper level divergence which was pumping mass away from the hurricane. Winds to hurricane force extended out about 45 miles (75 km) from the center of circulation. Winds to tropical storm force extended out about 185 miles (295 km) from the center.
Hurricane Barbara still rated at Category 4 on the Saffir-Simpson Scale. The Hurricane Intensity Index (HII) for Barbara was 28.3. The Hurricane Size Index (HSI) was 16.5 and the Hurricane Wind Intensity Size Index (HWISI) was 44.8.
Hurricane Barbara will gradually move into an environment less capable of supporting a strong hurricane during the next few days. Barbara will move over water where the Sea Surface Temperature is near 26°C. As a result, Hurricane Barbara will extract less energy from the upper ocean and it will gradually weaken. Barbara will move closer to an upper level trough located northeast of Hawaii. When Hurricane Barbara gets closer to the trough later this week, stronger upper level southwesterly winds will create more vertical wind shear and the hurricane will weaken more quickly.
Hurricane Barbara will move south of a subtropical ridge over the Eastern North Pacific Ocean. The ridge will steer Barbara toward the west-northwest during the next 24 to 36 hours. The ridge is forecast to strengthen on Friday and it will steer Hurricane Barbara more toward the west when that happens. On its anticipated track Barbara could approach Hawaii in about five days. It will be much weaker by that time.