Why It Matters
Hawaii residents are facing a dangerous and exhausting reality: barely two weeks after the state’s worst flooding in 20 years, another powerful storm system is threatening to undo recovery efforts and push communities already stretched thin into a new crisis. Ground saturated from previous storms will absorb less water, dramatically increasing the risk of rapid flooding and landslides across every island.
The timing could not be worse for thousands of Hawaiians whose homes and properties were damaged or destroyed in March’s catastrophic floods — and officials are urging residents not to underestimate the compounding danger.
What Happened
A potent, multi-day Kona storm began striking Hawaii on Tuesday afternoon, bringing the first rounds of heavy rain and triggering a flood watch for all of Hawaii through Friday afternoon. The National Weather Service has warned of significant flooding and landslide potential across every island in the chain.
This marks the third Kona storm to hit Hawaii since mid-March. The second triggered the worst flooding the state has seen in two decades, and communities remain in active recovery. Honolulu Mayor Rick Blangiardi addressed residents at a news conference Monday, issuing a stark warning.
“Be prepared for possible evacuations, this is what we’re anticipating. An island-wide event,” Blangiardi said. He added that Honolulu would activate its Emergency Operations Center Wednesday and deploy first responders to vulnerable areas ahead of the storm’s peak intensity.
Flash flood warnings were already issued Tuesday night for parts of Maui and the Big Island. Floodwater entered at least one home in the Big Island’s Puna District Tuesday night, according to the National Weather Service citing emergency management, with rainfall totals exceeding half a foot recorded at several nearby gauges.
By the Numbers
- A widespread 4 to 8 inches of rain is expected across Hawaii by Friday evening, with locally heavier amounts exceeding 10 inches possible.
- The Big Island and Kauai face the highest risk of accumulations in the heaviest rainfall bands.
- During March’s second Kona storm, one location on Oahu recorded 25 inches of rain, most of it falling within a single 24-hour period.
- The March flooding prompted more than 200 water rescues and damaged or destroyed hundreds of properties statewide.
- A widespread foot of rain fell across Oahu from March 19 to 24, triggering catastrophic flooding conditions.
Understanding Kona Storms
Kona storms are slow-moving weather systems that form and strengthen northwest of the Hawaiian Islands. Their sluggish movement allows them to continuously draw moisture from the equatorial Pacific, funneling relentless waves of rain across the islands over multiple days.
That slow movement is a key factor in the threat. Storms that linger allow rainfall to pile up in the same locations rather than passing quickly, and when the ground is already saturated from prior events, the danger escalates significantly.
“Every inch of rain, as far as we’re concerned, now is more than an inch of rain. It just compounds itself because of the circumstances and people need to be aware of that,” Blangiardi warned. Hawaii has seen a series of devastating emergencies in recent weeks, testing state and local emergency response systems.
Zoom Out
Hawaii’s struggle with back-to-back extreme weather events reflects a broader trend of compounding natural disasters straining state infrastructure and emergency management resources across the United States. When major flood events occur in rapid succession, recovery timelines stretch, costs multiply, and communities face diminishing windows to prepare for the next threat.
Infrastructure vulnerability is a central concern. Already-damaged roads, drainage systems, and hillsides weakened by the March storms are far more susceptible to catastrophic failure under renewed rainfall. The situation underscores the national conversation around infrastructure resilience and investment in hazard preparedness, a challenge that extends from Hawaii to states across the country.
What’s Next
Rounds of showers and thunderstorms are expected to move through Hawaii through Thursday morning before intensifying Thursday afternoon as the Kona storm reaches peak strength. The storm’s most dangerous period is anticipated Thursday into Friday as the heaviest rain bands track over the islands.
Rain is expected to remain in the forecast through the weekend but should become less intense by Saturday as the storm system moves north and away from the islands. Residents in flood-prone and previously impacted areas are urged to follow guidance from local emergency management and remain prepared to evacuate on short notice.
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