Iselle strengthens to category 3; Other systems developing


Hurricane Iselle approached Category 3 status Saturday, with 110 mph sustained winds. The system was located about 1,675 miles east of Hilo.

Hurricane force winds extended 25 miles from the center and storm force winds reached a radius of 105 miles. Iselle strengthened despite continued north-northeasterly wind shear and could intensify Sunday before beginning to weaken Monday, National Weather Service forecasters say.

“Iselle is going to be moving into cooler water and increased vertical wind shear,” forecaster Bob Burke said.

The cyclone was tracking west at 10 mph. Given it’s current trends, Iselle could be 250 miles east of the Big Island on Thursday, bringing 45 mph winds, Burke estimated. The system could carry moisture and humidity to the state late next week

Genevieve, meanwhile, redeveloped into a tropical storm Saturday as it passed well to the south of the islands. The window for this storm to impact Hawaii has passed, the forecaster said.

About 600 miles south of the Big Island, Genevieve was continuing a rapid west-southwest track away from Hawaii with sustained winds to 40 mph and was expected to intensify over the next several days. Storm force winds extend 70 miles from the center.

Iselle and Genevieve are part of a train of unsettled weather systems stretching through the Central and Eastern Pacific.

“It’s fairly active,” Burke said. “We’re here at the peak of the hurricane season in the Pacific.”

Behind Iselle, about 700 miles southwest of Manzanillo, Mexico, showers and thunderstorms around an area of low pressure are becoming better organized and have an 80 percent chance of becoming a tropical cyclone by Monday. The system is on a westward track at 10 mph.

And west of Iselle, about 1,000 miles southeast of Hilo, disorganized showers and thunderstorms are part of another low pressure system. The system’s development is expected to be hampered by upper level winds and any intensification should be slow as the system moves west at 12 mph.

The Central Pacific hurricane season started June 1 and ends Nov. 30.

“August and September are our peak months,” Burke said. “Generally into October things start to quiet down.”