A Tropical Storm Watch has been issued for Kauai County because of the potential effects of Hurricane Lowell. At 11:00 p.m. EDT on Saturday the center of Hurricane Lowell was located at latitude 13.7°N and longitude 163.4°W which put the center about 630 miles (1015 km) south-southwest of Lihue, Hawaii. Lowell was moving toward the west-northwest at 5 m.p.h. (8 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 942 mb.
A Tropical Storm Watch is in effect for Kauai County including Kauai and Niihau.
A Hurricane Watch is in effect for the Papahanaumokuakea Marine National Monument from Nihoa to French Frigate Shoals.
Hurricane Lowell weakened to Category 4 on the Saffir-Simpson Scale on Saturday. A circular eye with a diameter of 30 miles (50 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 more mass away from the hurricane. The removal of mass in the upper levels was less than the convergence of mass in the lowers levels of the atmosphere. So, the surface pressure increased on Saturday.
The distribution of wind speeds in Hurricane Lowell was fairly symmetrical. Winds to hurricane force extended out 45 miles (75 km) from the center of Lowell’s circulation. Winds to tropical storm force extended out 175 miles (280 km) from the center of Hurricane Lowell.
The Hurricane Intensity Index (HII) for Hurricane Lowell is 25.1. The Hurricane Size Index (HSI) is 18.8 and the Hurricane Wind Intensity Size Index (HWISI) is 43.9. Hurricane Lowell is similar in intensity to Hurricane Harvey when Harvey hit Texas in 2017. Hurricane Lowell is larger than Harvey was.
Hurricane Lowell will move through an environment that will be a little less 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. However, Lowell will start to move into a mass of drier air on Sunday. Hurricane Lowell is likely to continue to weaken slowly on Sunday because of the effects of the drier air.
Hurricane Lowell will move around the western end of a high pressure system that is over the Central North Pacific Ocean. The high pressure system will steer Lowell toward the north during the next 24 hours. On its anticipated track, Hurricane Lowell will start to move closer to Kauai and Niihau on Sunday.
Elsewhere, former Hurricane Karina weakened to a tropical storm east of Hawaii and Hurricane Marie started to weaken west of Baja California.
At 11:00 p.m. EDT on Saturday the center of Tropical Storm Karina was located at latitude 22.0°N and longitude 143.9°W which put the center about 740 miles (1190 km) east-northeast of Hilo, Hawaii. Karina was moving toward the west-northwest at 6 m.p.h. (10 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 993 mb.
At 11:00 p.m. EDT on Saturday the center of Hurricane Marie was located at latitude 22.6°N and longitude 121.3°W which put the center about 725 miles (1170 km) west of the southern tip of Baja California. Marie was moving toward the northwest at 6 m.p.h. (10 km/h). The maximum sustained wind speed was 90 m.p.h. (145 km/h) and there were wind gusts to 105 m.p.h. (165 km/h). The minimum surface pressure was 970 mb.