Hawaii braces for another major Kona storm as heavy rain renews flood threat across the islands

Rain returns before recovery is complete

The islands are still drying out, but the rain has already returned.

A new Kona storm has begun to move across Hawaii, bringing fresh rounds of heavy rain just weeks after the state experienced its worst flooding in 20 years. The pattern feels familiar. Clouds build, rain settles in, and the ground responds quickly.

This is now the third Kona storm since mid-March.

A flood watch has been issued for all of Hawaii through Friday afternoon, signaling the potential for widespread flooding and landslides.

Heavy rainfall spreads across the islands

The storm is expected to deliver significant rainfall over several days.

Forecast totals point to:

• 4 to 8 inches of widespread rain
• locally more than 10 inches in some areas

The Big Island and Kauai are most likely to see the highest totals, but the structure of the storm leaves open the possibility that any island could experience the heaviest bands.

Rain does not fall evenly in these systems. It concentrates. It repeats.

Officials warn of evacuations as risk increases

Authorities are preparing for a serious situation.

“Be prepared for possible evacuations, this is what we are anticipating. An island-wide event," said Honolulu Mayor Rick Blangiardi, as emergency measures were put in place ahead of the storm.

Honolulu, HI has activated its Emergency Operations Center, and first responders are being positioned in vulnerable areas as the storm strengthens.

The concern is not only the rain itself, but what follows.

Saturated ground raises flood and landslide danger

The islands are entering this storm already weakened by previous rainfall.

During the second Kona storm in March, Oahu, HI recorded widespread rainfall totals approaching a foot, with some locations receiving as much as 25 inches in a single event. That storm triggered catastrophic flooding, more than 200 rescues, and extensive damage.

The ground has not fully recovered.

“Every inch of rain, as far as we are concerned, now is more than an inch of rain," Blangiardi said. “It just compounds itself because of the circumstances and people need to be aware of that."

Water now runs off faster. Slopes give way more easily.

Flooding already reported as storm intensifies

The first impacts have already been observed.

Showers began moving across the islands Tuesday afternoon and continued into Wednesday morning, prompting flash flood warnings in parts of Maui, HI and the Big Island, HI.

In the Puna District on the Big Island, floodwater entered at least one home, as nearby gauges recorded rainfall totals exceeding half a foot.

The storm builds in stages. Each round adds pressure.

Stronger storms expected as system develops

Conditions are expected to worsen as the storm strengthens.

Periods of showers and thunderstorms will continue through Thursday morning, with a noticeable increase in intensity expected later in the day. Bands of rain may track repeatedly over the same areas, producing large amounts of rainfall in short periods.

This is how totals climb quickly.

Rain trains over the same ground. Water accumulates.

Rain continues into the weekend before easing

The pattern does not end immediately.

Rain is expected to remain across much of Hawaii through the weekend, though intensity should gradually decrease as the system shifts north and away from the islands by Saturday.

Even then, the effects linger.

The ground remains saturated. The water stays in motion.