Tropical Storm Olivia moved closer to Hawaii on Tuesday. At 5:00 p.m. EDT on Tuesday the center of Tropical Storm Olivia was located at latitude 21.6°N and longitude 152.3°W which put it about 275 miles (440 km) east of Kahului, Hawaii. Olivia was moving toward the west at 17 m.p.h. (28 km/h). The maximum sustained wind speed was 60 m.p.h. (95 km/h) and there were wind gusts to 75 m.p.h. (120 km/h). The minimum surface pressure was 1000 mb.
Tropical Storm Warnings were in effect for Oahu, Hawaii County, Maui County including Maui, Molokai, Lanai and Kahoolawe, and for Kauai County including Kauai and Niihau.
Tropical Storm Olivia was weakening as it neared Hawaii. An upper level trough north of Hawaii was producing strong westerly winds which were blowing across the top of the circulation. Those winds caused significant vertical wind shear and they blew the tops off thunderstorms near the center of circulations. Bands near the center and in the western half of Tropical Storm Olivia consisted primarily of showers and lower clouds. There were still a few taller thunderstorms in bands on the far eastern side of the circulation.
Since Tropical Storm Olivia consisted mostly of a circulation in the lower levels of the atmosphere, it was being steered by the winds in the lower levels. Olivia was moving south of the subtropical high over the central Pacific Ocean. That high steered Tropical Storm Olivia quickly to the west on Tuesday and it will continue to do so. On its anticipated track Tropical Storm Olivia will reach Hawaii on Wednesday. Olivia will bring some gusty winds and it could drop locally heavy rain, especially where the wind rises over hills and mountains.
Tropical Storm Olivia formed south of Baja California on Sunday morning. At 11:00 a.m. EDT on Sunday the center of Tropical Storm Olivia was located at latitude 17.0°N and longitude 112.4°W which put it about 440 miles (705 km) south-southwest of the southern tip of Baja California. Olivia was moving toward the northwest at 7 m.p.h. (11 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 1002 mb.
The circulation of Tropical Storm Olivia was not well organized. Most of the stronger thunderstorms were occurring in bands southwest of the center of circulation. The bands in the other parts of the tropical storm consisted primarily of showers and lower clouds. Olivia was located southeast of an upper level ridge. The ridge was producing northeasterly winds which were blowing across the top of the circulation. Those winds were causing vertical wind shear and they were probably the reason why the stronger thunderstorms were confined to the southwestern part of Tropical Storm Olivia.
Tropical Storm Olivia will move into an environment that is more favorable for intensification. Olivia will move over water where the Sea Surface Temperature is near 29°C. It will move away from the northeasterly winds in the upper levels and the vertical wind shear is likely to decrease. Intensification will occur slowly until the circulation becomes more well organized. Once more thunderstorms form in other parts of the circulation, Tropical Storm Olivia could strengthen more quickly.
Tropical Storm Olivia will move south of a ridge of high pressure over the Eastern North Pacific Ocean. The ridge will steer Olivia in a westerly direction during the next several days. On its anticipated track Tropical Storm Olivia will move away from Baja California.
Elsewhere over the Eastern North Pacific Ocean, Hurricane Norman strengthened back to Category 4 on the Saffir-Simpson Scale. At 11:00 a.m. EDT on Sunday the center of Hurricane Norman was located at latitude 17.6°N and longitude 129.1°W which put it about 1295 miles (2085 km) west-southwest of the southern tip of Baja California. Norman was moving toward the west-northwest at 18 m.p.h. (30 km/h). The maximum sustained wind speed was 130 m.p.h. (215 km/h) and there were wind gusts to 160 m.p.h. (260 km/h). The minimum surface pressure was 949 mb. Norman could be northeast of Hawaii in four or five days.