Tropical Storm Moke Targets Hawaii's Big Island Days After Hurricane Lala's Deadly Flooding

Hawaii's Big Island got a break from the rain for about five days. That break ends Saturday night.

Tropical Storm Moke formed Friday morning, August 21, with maximum sustained winds of 45 mph, according to the Central Pacific Hurricane Center. As of 5 p.m. Friday, the storm's center sat roughly 600 miles southeast of Hilo, moving west-northwest at 12 mph, the Honolulu Star-Advertiser reported.

Forecasters expect Moke to stay south of the islands and remain below hurricane strength, unlike its predecessor. The National Hurricane Center and CPHC both say the odds of tropical storm watches or warnings for the main Hawaiian islands are low, per the Star-Advertiser.

Rain doesn't need a direct hit to cause damage. The storm is forecast to bring 5 to 10 inches of rain to the Big Island, with maximum totals up to 15 inches, according to ABC News and the National Weather Service data cited by Weather.com. Some Weather.com modeling puts the top end as high as 15 inches specifically over the mountains and eastern slopes. Rain is expected to arrive late Saturday, hit hardest Sunday, and linger into Monday.

A flood watch is in effect for the Big Island from late Saturday night through Monday afternoon, according to Maui Now and the Star-Advertiser. The rest of the island chain should see lighter totals, 1 to 4 inches, with localized flash flood risk over mountains and slopes.

Ground already saturated from Lala

The timing presents a significant challenge. Hurricane Lala hit the islands as a Category 1 storm roughly a week earlier, dumping more than a foot of rain across parts of the state and over 40 inches at the highest elevations, according to ABC News. Gov. Josh Green said one person died in a storm-related car crash on the Big Island's southern end, and Hawaii County Mayor Kimo Alameda ordered a search-and-rescue mission after flash flooding in Naalehu and Waiohinu tore homes off their foundations, the Daily Wire reported.

More than 130,000 households lost power across Hawaii's three largest islands during Lala, per NPR figures cited by the Daily Wire. ABC News reports Lala damaged or destroyed more than 100 homes on the Big Island and that thousands there remain without power.

Hawaiian Electric has said some customers in the southeast Big Island could stay without power through Labor Day weekend, with 95% restoration expected by September 8, according to the Epoch Times, which cited the utility's statement on X. That timeline assumes Moke doesn't slow down repair crews. "Due to significant storm damage, customers in certain remote or severely damaged areas should prepare to be without power for much longer periods of time," the company said.

Soil that's already saturated absorbs less water, which raises flash flood and landslide risk even from a storm passing well offshore. Both the Star-Advertiser and Weather.com flagged this directly: ground conditions from Lala could "aggravate the impacts" of Moke's rain.

How this compares to Lala

Lala was the rarer, more dangerous event. Breitbart's pre-storm coverage, drawn from an Associated Press report, quoted National Weather Service meteorologist Vanessa Almanza noting that a hurricane hadn't made landfall on the Big Island since 1871, based on a professor's research of historical newspaper accounts. Lala came close to the southern tip but didn't technically make landfall as it passed south of the island.

Moke is a smaller, weaker system. The National Hurricane Center's own outlook, cited by the Epoch Times before Moke was named, gave the disturbance a 90% chance of organizing into a cyclone, and said models generally kept it offshore, passing near the Big Island's southern point around August 23. That has largely held up: Moke intensified into a tropical storm right on schedule Friday morning, per Maui Now, and is tracking south of the chain.

Weather.com notes that back-to-back tropical threats hitting Hawaii within one week have happened only once before since 1950, underscoring how unusual this stretch has been.

What's still uncertain

Moke could strengthen slightly over the next day or two, according to the CPHC, but wind shear and drier air are expected to cap its intensity. The bigger variable is rainfall distribution. Weather.com's range of 5 to 15 inches and ABC News's range of 5 to 10 inches with a 15-inch max each highlight the same risk: isolated pockets over the mountains and eastern slopes could see far more rain than the broader forecast average.

Hawaii County officials have not yet announced new shelter openings or school closures tied to Moke, unlike the closures Gov. Green ordered ahead of Lala. Whether that changes depends on how the storm's track evolves over the weekend, and how much more damage saturated hillsides can absorb before Hawaiian Electric's already-strained restoration timeline slips further.