Hurricane Calvin churned toward the Central Pacific Ocean on Saturday. At 5:00 p.m. EDT on Saturday the center of Hurricane Calvin was located at latitude 15.0°N and longitude 130.4°W which put it about 1660 miles (2670 km) east of Hilo, Hawaii. Calvin was moving toward the west at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h). The minimum surface pressure was 975 mb.

Hurricane Calvin weakened on Saturday when it moved over cooler water east of Hawaii. Thunderstorms around the center of Calvin’s circulation did not rise as high into the atmosphere. The structure of Hurricane Calvin remained well organized even though the hurricane was weaker. A small circular eye was still present at the center of Calvin’s circulation. The eye was surrounded by a broken ring of thunderstorms and the strongest winds were occurring in that ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Calvin. Storms near the core still generated upper level divergence that pumped mass away from the hurricane.

The circulation around Hurricane Calvin was small. Winds to hurricane force extended out 25 miles (40 km) from the center of Calvin’s circulation. Winds to tropical storm force extended out 105 miles (165 km) from the center of circulation. The Hurricane Intensity Index (HII) for Hurricane Calvin was 16.5. The Hurricane Size Index (HSI) was 9.3 and the Hurricane Wind Intensity Size Index (HWISI) was 25.8.

Hurricane Calvin will move through an environment that will be unfavorable for intensification during the next 24 hours. Calvin will move over water where the Sea Surface Temperatures are near 25˚C. It will move through a region where then upper level winds that are weak and there will be little vertical wind shear. Hurricane Calvin will continue to weaken during the next 24 hours because of the cooler water even though there will be little vertical wind shear.

Hurricane Calvin will move around the southern part of a subtropical high pressure system over the Eastern and Central Pacific Ocean. The high pressure system will steer Calvin toward the west during the next several days. On its anticipated track, Hurricane Calvin will continue to move toward the Central Pacific Ocean. Calvin could approach Hawaii on Tuesday. Calvin could still be a tropical storm when it approaches Hawaii.