Hurricane Lowell rose to Category 5 south of Hawaii, and its turn north stays uncertain
The Central Pacific Hurricane Center confirmed Lowell rapidly intensified into a Category 5 hurricane on September 2, with maximum sustained winds near 260 km/h about 715 km south of Hilo, then eased back to Category 4. Forecasters kept it a major hurricane through the weekend ahead of a sharp northward turn they call more uncertain than usual. Karina held Category 4 strength farther east and Marie became a hurricane off Baja California.
Science··Midday
Lowell climbs to Category 5, then eases back
Hurricane Lowell rapidly intensified on the morning of September 2, and the Central Pacific Hurricane Center confirmed it had reached Category 5, with maximum sustained winds near 260 km/h about 715 km south of Hilo. The National Weather Service advisory earlier that morning had placed Lowell at Category 4 on the Saffir-Simpson scale, with winds near 250 km/h, a minimum central pressure of 932 mb and further strengthening in prospect. By late afternoon the storm had eased back to Category 4 and was moving west at 16 km/h, with hurricane-force winds reaching about 55 km from the centre and tropical-storm-force winds about 145 km; a NOAA hurricane hunter aircraft collected the latest data on the compact system. The Phys.org report of the same day placed Lowell and Karina, both Category 4 hurricanes as it was written, south of and northeast of Hawaii on National Hurricane Center forecasts.[1], [2], [3]
The sharp turn north and Hawaii's advisories
Forecasters expect Lowell to slow and turn sharply toward the north or north-northeast over the weekend, with a cutoff mid- to upper-level low forecast to drop southwestward and weaken the steering ridge. The Central Pacific Hurricane Center said the details of the long-range track and intensity forecasts are more uncertain than usual, and the National Weather Service pointed to large model spread and above average uncertainty around that anticipated turn. On the five-day track Lowell would be a strong Category 3 storm with winds near 200 km/h by Monday afternoon, centred about 480 km southwest of Lihue, and forecasters kept high confidence that it stays a major hurricane through the weekend. Officials said it is too soon to determine potential impacts in the Hawaiian Islands, and Honolulu Mayor Rick Blangiardi asked residents to use the extra days to check emergency plans and supplies. The National Weather Service issued a wind advisory from Hawaii island to Oahu into Friday morning and a high surf advisory for south and southeast shores with breaking waves of 2 to 3 metres, while swells spreading from Lowell were expected to bring life-threatening surf and rip currents to some coasts.[1], [2]
Karina weakens as Marie becomes a hurricane
Farther east, Karina remained a Category 4 hurricane with winds of about 235 km/h roughly 2,320 km west of the southern tip of Baja California and was expected to weaken to a tropical storm within days; by late afternoon it carried winds near 210 km/h about 2,130 km east of Hilo, forecast to be post-tropical by Monday. Marie, a tropical storm with maximum sustained winds near 105 km/h about 700 km south of the same point that morning, became a hurricane later in the day about 600 km southwest of the tip of Baja California. Julia Cole, a climate scientist at the University of Michigan, describes El Niño warming as setting the stage for storms that draw their energy largely from warm water, and separates the driving factor from the trend: a warming atmosphere holds more moisture and amplifies what an El Niño delivers, while whether warming makes El Niño events themselves stronger has less agreement behind it. This year's El Niño carried a 69 per cent chance of becoming the strongest yet measured and was not expected to peak until around November.[1], [2], [3]
