Tropical Storm Moke strengthens slightly; will bring heavy rain to Big Island

Tropical Storm Moke strengthened slightly overnight and remains on a path that will bring it within a couple of hundred miles south of the Big Island late tonight and even farther south of the rest of the state Sunday and Monday.

At 5 a.m. today, Moke had 50 mph maximum sustained winds and was centered about 470 miles southeast of Hilo, moving west-northwest at 12 mph, according to the Central Pacific Hurricane Center. Tropical storm-force winds extend up to 115 miles from the center.

The passing tropical storm is expected to bring gusty winds and heavy rain, up to 15 inches in some areas, to Hawaii island starting tonight. The island, which is still recovering from the devastation of Hurricane Lala last weekend, is under a flood watch from late tonight through Monday afternoon, according to the National Weather Service.

“Rainfall totals of 5 to 10 inches, locally up to 15 inches, are possible over the windward and southeast slopes of the Big Island,” the flood watch says. “It will not take a significant amount of rain to cause flash flooding due to saturated ground from recent heavy rain.”

Rainfall totals of 1 to 2 inches, with maximum amounts of 4 inches, are expected on eastern Maui, while the rest of the state may see totals of 1 to 2 inches.

The weather service also posted a wind advisory from noon today until 6 p.m. Sunday for portions of Maui, Molokai, Lanai, Kahoolawe and the Big Island, saying that “the strongest sustained winds will occur over mountain ridges, gaps and where winds blow downslope from higher terrain.”

The advisory predicts east-northeast winds of 25 to 35 mph with gusts up to 55 mph. “Winds this strong can tear off shingles, knock down tree branches, blow away tents and awnings, and make it difficult to steer, especially for drivers of high-profile vehicles,” forecasters said.

Moke is a smaller storm than Lala and is expected to travel much farther south than last weekend’s cyclone, which lingered close to South Point for most of Aug. 15 as a Category 1 hurricane then skirted just south of the smaller islands through Monday.

“Since Moke is expected to remain compact, and because there is high confidence in the short-term track forecast, no tropical storm watches or warnings appear to be necessary for Hawaii,” forecasters said this morning. “However, the storm is expected to be close enough to produce gusty winds in portions of the Hawaiian Islands, especially in areas of high terrain, late tonight through early next week. In addition, most of the associated moisture is expected to be on the north side of the cyclone, so areas of heavy rain are forecast there during the next few days.”

Moke’s maximum sustained winds may peak at about 60 mph later today but are expected to weaken over the next four days as it moves past the islands. The latest five-day forecast has no island in the so-called cone of uncertainty, indicating that a direct hit is not expected for Hawaii.

NOAA and Air Force Hurricane Hunters have flown in and around the storm to gather data and are scheduled to investigate the system again later today, weather officials said.

In addition to heavy rain for the Big Island and gusty winds across the state, Moke is expected to generate high surf along east and south shores of the islands over the next few days.

“These swells may cause life-threatening surf and rip current conditions,” CPHC forecasters said. No surf advisories or watches were in effect as of early this morning.

The National Hurricane Center in Miami, meanwhile, is watching three weather systems in the East Pacific, south of Baja California, that may develop into tropical cyclones in the next week.