Hurricane Lowell moved south of Hawaii on Thursday.  At 11:00 p.m. EDT on Thursday the center of Hurricane Lowell was located at latitude 13.5°N and longitude 158.9°W which put the center about 590 miles (945 km) south of Lihue, Hawaii.  Lowell was moving toward the west at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 130 m.p.h. (210 km/h) and there were wind gusts to 155 m.p.h. (250 km/h).  The minimum surface pressure was 943 mb.

Hurricane Lowell weakened a little on Thursday as it moved south of Hawaii.  An eyewall replacement cycle may have led to the weakening of Lowell.  A circular eye with a diameter of 17 miles (28 km) was still at the center of Lowell’s circulation.  The eye was surrounded by a ring of thunderstorms and the strongest winds were occurring in that ring of storms.  Bands of showers and thunderstorms were revolving around the center of Hurricane Lowell.  Storms near the center generated upper level divergence that pumped mass away from the hurricane. The removal of mass in the upper levels was less than the convergence of mass in the lower levels of the atmosphere.  An accumulation of mass caused the surface pressure to increase on Thursday.

The eyewall replacement cycle cause the size of the circulation around Hurricane Lowell to increase.  Winds to hurricane force extended out 45 miles (75 km) from the center of Lowell’s circulation.  Winds to tropical storm force extended out 140 miles (225 km) from the center of Hurricane Lowell.

The Hurricane Intensity Index (HII) for Hurricane Lowell is 25.1.  The Hurricane Size Index (HSI) is 14.6 and the Hurricane Wind Intensity Size Index (HWISI) is 39.7.  Hurricane Lowell is similar in size and intensity to Hurricane Harvey when Harvey hit Texas in 2017.

Hurricane Lowell will move through an environment favorable for intensification during the next 24 hours.  Lowell will move over water where the Sea Surface Temperatures are near 28°C. It will move through a region where the upper level winds are weak and there will be little vertical wind wind shear.  Hurricane Lowell could intensify during the next 24 hours after the eyewall replacement cycle is fully completed.

Hurricane Lowell will move around the southern side of a high pressure system that is over the Central North Pacific Ocean.  The high pressure system will steer Lowell toward the west during the next 24 hours.  On its anticipated track, Hurricane Lowell will remain south of Hawaii on Friday.  Lowell is forecast to start moving toward the north by the end of the weekend.

Elsewhere, Hurricane Karina continued to weaken gradually and Hurricane Marie intensified to Category 2 on the Saffir-Simpson Scale.

At 11:00 p.m. EDT on Thursday the center of Hurricane Karina was located at latitude 20.1°N and longitude 138.4°W which put the center about 1085 miles (1745 km) east of Hilo, Hawaii.  Karina was moving toward the west-northwest at 9 m.p.h. (15 km/h).  The maximum sustained wind speed was 105 m.p.h. (165 km/h) and there were wind gusts to 125 m.p.h. (200 km/h).  The minimum surface pressure was 969 mb.

At 11:00 p.m. EDT on Thursday the center of Hurricane Marie was located at latitude 19.6°N and longitude 116.3°W which put the center about 470 miles (755 km) west-southwest of the southern tip of Baja California.  Marie was moving toward the west-northwest at 9 m.p.h. (15 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 972 mb.