Hawaiʻi County declares emergency as Tropical Storm Moke raises flood risk on Lala-damaged Big Island

The storm’s minimum central pressure was 1 002 hPa, and it was moving west-northwest at 20 km/h (12 mph). Tropical-storm-force winds extended up to 185 km (115 miles) from the center across the northern semicircle, while no coastal watches or warnings were in effect.

Persistent southwesterly vertical wind shear and dry mid-level air had eroded much of Moke’s earlier convection and exposed its low-level circulation. Satellite and Air Force Reserve reconnaissance observations supported maintaining the cyclone at tropical-storm strength.

The center was forecast to pass approximately 320 km (200 miles) south of the Big Island on August 23 before moving well south of the smaller main Hawaiian Islands. The strongest winds were expected to remain offshore, but strong gusts were forecast within and downslope of higher terrain.

A Flood Watch covers the Big Island from 00:00 HST on August 23 until 18:00 HST on August 24. Rainfall totals of 127–254 mm (5–10 inches), with isolated amounts up to 381 mm (15 inches), are forecast over windward and southeastern areas.

Saturated ground left by recent heavy rain means relatively little additional rainfall could trigger flash flooding. Possible impacts include overflowing streams, road closures, rapid urban runoff, property flooding and mudslides in steep terrain.

Eastern Maui is forecast to receive 76–152 mm (3–6 inches). Moisture drawn north of Moke could bring 25–51 mm (1–2 inches) to western Maui and the other islands.

A Wind Advisory remains in effect for portions of Maui County and the Big Island through 18:00 HST on August 23. East-northeast winds of 40–56 km/h (25–35 mph), with gusts up to 90 km/h (55 mph), are forecast, with the strongest winds expected over ridges, through gaps and where winds accelerate downslope.

Swells generated by Moke are expected to affect exposed eastern and southern shores, producing hazardous surf and rip currents. Small Craft Advisories cover numerous coastal waters, while periods of heavy rain and instrument flight rules conditions are forecast over windward parts of the Big Island.

Hawaiʻi County announced the local state of emergency on August 22 because of the combined risk from Moke and infrastructure damage, power outages and saturated ground left by Lala. Residents in flood-prone or otherwise unsafe areas were advised to relocate before conditions deteriorated.

Six shelters were scheduled to be operating by 20:00 HST on August 22. They are Nāʻālehu Elementary School gym, Robert N. Herkes Gym in Pāhala, Pāhoa Senior Center, Keaʻau Armory, Puʻuʻeo Community Center in Hilo and Sgt. Rodney J.T. Yano Memorial Hall in Captain Cook.

Nāʻālehu Elementary School gym and Robert N. Herkes Gym were already operating on generator power when the shelter announcement was issued. The shelters are pet-friendly, although animals must be kept in carriers.

Hele-On bus routes 2, 10, 12 and 90 were cancelled for August 23. The 06:15 HST southbound and 15:03 HST northbound trips on route 75 were also cancelled, while delays, rerouting or additional cancellations remained possible.

No Moke-related casualties, structural damage or confirmed flooding had been reported in the official updates available early on August 23. The Flood Watch indicates that flash flooding is possible and should not be presented as confirmation that flooding has occurred.

Moke arrived while recovery from Lala continued. Hawaiian Electric reported that approximately 8 800 customers remained without power on Hawaiʻi Island at 09:00 HST on August 22, after service was restored to about 2 500 customers during the preceding day.

Restoration estimates varied according to damage and access. Full restoration in parts of Kaʻū, including Waiʻōhinu, Nāʻālehu, Punaluʻu, Pāhala and Wood Valley, could extend to September 8, although many customers were expected to regain service sooner.

All Hawaiʻi County Department of Water Supply customers remained under an essential-use-only request until further notice. Lala-related power outages continued affecting water-system operations and had caused low pressure or loss of service in some locations.

Transportation crews continued repairing Māmalahoa Highway, Route 11, in Kaʻū. Access between Pāhala and Waiʻōhinu, from mileposts 49 to 69.5, remained limited to residents and disaster-response traffic, with major repairs underway near Pāhala Hospital and Nāʻālehu Cemetery.

The washout near Pāhala Hospital measured approximately 8 m (25 feet) deep, 64 m (211 feet) long and 13 m (44 feet) wide. Crews had filled approximately 5 m (17 feet) of the damaged section by August 21.

Bridges along the affected Route 11 corridor had been inspected and were structurally sound and safe for operations. Single-lane closures with alternating traffic control remained possible while crews cleared debris from streams and repaired damaged sections.

Near Nāʻālehu Cemetery, debris removal was being coordinated with state and county emergency-management agencies monitoring for possible human remains displaced by Lala.

At Hilo International and Ellison Onizuka Kona International airports, crews reinspected drainage systems, trimmed trees, secured equipment, tied down or relocated aircraft and filled emergency generators. Staff at airports in Maui County and at Līhuʻe were also placed on standby.

Moke developed from Invest 90E and became Tropical Depression Two-C at 05:00 HST on August 20. The depression was then approximately 1 545 km (960 miles) east-southeast of Hilo, with maximum sustained winds of 55 km/h (35 mph), a minimum pressure of 1 006 hPa and a west-northwest motion of 26 km/h (16 mph).

Air Force Reserve reconnaissance observations and improved curved banding led to the system’s upgrade to Tropical Storm Moke at 11:00 HST on August 21. Moke reached maximum sustained winds of 85 km/h (50 mph) early on August 22 before weakening to 75 km/h (45 mph).

Gradual weakening was forecast to begin on August 23 as dry, stable air continued entering the circulation. Moke could become a post-tropical remnant low around August 27 and dissipate around August 28.

The Central Pacific hurricane season runs from June 1 through November 30. NOAA’s 2026 outlook assigned a 70% probability of an above-normal season and forecast 5–13 tropical cyclones, including tropical depressions, named storms and hurricanes.

References:

¹ Area Forecast Discussion and active hazard information for Hawaiʻi – NWS – August 23, 2026.

² HDOT preparations for heavy rains from Tropical Storm Moke – Hawaii DOT – August 21, 2026

³ Emergency Proclamation Relating to Tropical Storm Moke – County of Hawaiʻi – August 22, 2026

⁴ Tropical Storm Moke Advisory Number 12 – NOAA/NHC – August 23, 2026