An Air Force Reserve Hurricane Hunter reconnaissance aircraft found on Monday that Hurricane Hector had strengthened to nearly Category 5 on the Saffir-Simpson Scale. At 5:00 p.m. EDT on Monday the center of Hurricane Hector was located at latitude 15.2°N and longitude 143.1°W which put it about 870 miles (1405 km) east-southeast of South Point, Hawaii. Hector was moving toward the west at 16 m.p.h. (26 km/h). The maximum sustained wind speed was 155 m.p.h. (250 km/h) and there were wind gusts to 190 m.p.h. (305 km/h). The minimum surface pressure was 936 mb. A Tropical Storm Watch is in effect for Hawaii County.
Hurricane Hector has a very symmetrical, well formed circulation. There is a circular eye with a diameter of 19 miles (31 km) at the center of circulation. The eye is 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 Hector. Storms near the core were generating well developed upper level divergence which was pumping mass away from the hurricane in all directions.
The circulation of Hurricane Hector is compact. Winds to hurricane force extend out about 35 miles (55 km) from the center of circulation. Winds to tropical storm force extend out about 105 miles (170 km) from the center. The Hurricane Intensity Index (HII) for Hurricane Hector is 33.3. The Hurricane Size Index (HSI) is 12.1 and the Hurricane Wind Intensity Size Index (HWISI) is 45.4.
Hurricane Hector will remain in its current environment for several more days. Hector will move over water where the Sea Surface Temperature is near 27°C. It will move through a region where the upper level winds are weak and there will be little vertical wind shear. If a rainband wraps around the eye and eyewall, then an eyewall replacement cycle could occur. Eyewall replacement cycles cause weakening at first while the inner eyewall dissipates. Hurricanes can restrengthen if the outer eyewall starts for move closer to the center of circulation. Most very powerful hurricanes only stay very intense for 12 to 24 hours before they start to weaken. If takes a lot of energy to drive an intense hurricane and if Hector moves into an environment that is a little less favorable, then it could weaken.
Hurricane Hector will move south of the subtropical high pressure system over the Eastern and Central North Pacific Ocean. The subtropical high will steer Hector in a general westerly direction during the next few days. On its anticipated track Hurricane Hector will be southeast of Hawaii by Wednesday morning. The core of Hurricane Hector is forecast to pass south of Hawaii, but it could come close enough to cause tropical storm force winds which is the reason for the Tropical Storm Watch.