Former Tropical Storm Calvin intensified to a hurricane on Thursday morning. At 11:00 a.m. EDT on Thursday the center of Hurricane Calvin was located at latitude 12.7°N and longitude 117.1°W which put it about 850 miles (1365 km) southwest of the southern tip of Baja California. Calvin was moving toward the west at 13 m.p.h. (20 km/h). The maximum sustained wind speed was 75 m.p.h. (120 km/h) and there were wind gusts to 90 m.p.h. (145 km/h). The minimum surface pressure was 993 mb.
Former Tropical Storm Calvin intensified rapidly to a hurricane during the past 30 hours. The inner end of rainband wrapped around the center of Hurricane Calvin’s circulation. An eye was beginning to appear at the center of circulation on satellite images. The eye was surrounded by a broken ring of thunderstorms. The strongest winds were occurring in the northeastern part of the ring of storms. Bands of showers and thunderstorms were revolving around the core of Hurricane Calvin. Storms near the core 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) in the northeastern quadrant of Calvin’s circulation. Winds to tropical storm force extended out 70 miles (110 km) from the center of Hurricane Calvin.
Hurricane Calvin will move through an environment that will be favorable for intensification during the next 24 hours. Calvin will move over water where the Sea Surface Temperatures are near 28˚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 intensify during the next 24 hours. Calvin could intensify rapidly at times once the inner core is more fully formed.
Hurricane Calvin will move around the southern part of a subtropical high pressure system over the Eastern North Pacific Ocean. The high pressure system will steer Calvin toward the west during the next several days. On its anticipated track, Hurricane Calvin will move toward the Central Pacific Ocean. Calvin is likely to weaken when it moves over cooler water in the Central Pacific, but it could be east of Hawaii by early next week.