Strong vertical wind shear weakened Tropical Storm Hilda again on Wednesday and the Tropical Storm Watch for the Big Island of Hawaii was discontinued by the Central Pacific Hurricane Center.  At 11:00 p.m. EDT on Wednesday the center of Tropical Storm Hilda was located at latitude 17.2°N and longitude 152.4°W which put it about 245 miles (395 km) southeast of Hilo, Hawaii.  Hilda was moving toward the west at 4 m.p.h. (6 km/h).  The maximum sustained wind speed was 45 m.p.h. (75 km/h) and there were wind gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1003 mb.

An upper level low north of the Hawaiian Islands is generating very strong southwesterly winds that are blowing right over the top of Tropical Storm Hilda.  Those winds are blowing thunderstorms away from the core of the circulation.  The western half and inner core of Hilda consists of bands of low clouds rotating counterclockwise around the exposed center of circulation.  Thunderstorms continue to form in some of the bands northeast of the center of circulation, but the strong upper level winds quickly blow the tops off of those storms.  Since the upper level low isn’t moving, strong vertical wind shear is expected to continue and Hilda should slowly spin down.  It is likely to weaken to tropical depression status on Thursday.

As the circulation gets shallower, Hilda will be steered by the winds in the lower atmosphere.  Those winds are blowing from the east and the will push the tropical storm or its remnants toward the west.  On its anticipated track Hilda would pass south of Hawaii as a tropical depression during the next several days.