Hilo

Tonight: Scattered showers in the evening, then occasional showers after midnight. Lows 69 to 76 near the shore to around 64 at 4000 feet. North winds up to 15 mph. Chance of rain near 100 percent.

Thursday: Cloudy with occasional showers and slight chance of thunderstorms. Locally heavy rainfall possible. Highs around 84 near the shore to around 70 at 4000 feet. East winds up to 15 mph. Chance of rain 90 percent.

Thursday Night: Cloudy. Occasional showers and slight chance of thunderstorms in the evening, then showers likely after midnight. Locally heavy rainfall possible. Lows 68 to 75 near the shore to around 61 at 4000 feet. East winds up to 10 mph. Chance of rain 90 percent.

Kona

Tonight: Partly cloudy with isolated showers. Lows 72 to 78 near the shore to 58 to 63 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny with isolated showers and slight chance of thunderstorms in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs around 90 near the shore to around 74 near 5000 feet. Southwest winds up to 10 mph shifting to the northwest in the afternoon. Chance of rain 50 percent.

Thursday Night: Mostly cloudy with scattered showers and slight chance of thunderstorms in the evening, then partly cloudy with scattered showers after midnight. Locally heavy rainfall possible. Lows 71 to 78 near the shore to around 60 near 5000 feet. East winds up to 10 mph shifting to the northeast after midnight. Chance of rain 40 percent.

Waimea

Tonight: Breezy. Mostly cloudy with showers likely. Lows 69 to 77 near the shore to 64 to 71 near 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph after midnight. Chance of rain 70 percent.

Thursday: Mostly cloudy. Breezy. Scattered showers and slight chance of thunderstorms in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible. Highs around 84 near the shore to 73 to 83 near 3000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Thursday Night: Mostly cloudy. Showers likely and slight chance of thunderstorms in the evening, then showers likely after midnight. Locally heavy rainfall possible. Lows 68 to 76 near the shore to 63 to 70 near 3000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Kohala

Tonight: Breezy. Mostly cloudy with showers likely. Lows 69 to 77 near the shore to 64 to 71 near 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph after midnight. Chance of rain 70 percent.

Thursday: Mostly cloudy. Breezy. Scattered showers and slight chance of thunderstorms in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible. Highs around 84 near the shore to 73 to 83 near 3000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Thursday Night: Mostly cloudy. Showers likely and slight chance of thunderstorms in the evening, then showers likely after midnight. Locally heavy rainfall possible. Lows 68 to 76 near the shore to 63 to 70 near 3000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

South Big Island

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 78 near the shore to around 63 near 5000 feet. Light winds becoming north up to 10 mph after midnight. Chance of rain 40 percent.

Thursday: Mostly sunny in the morning then becoming partly sunny. Breezy. Scattered showers and slight chance of thunderstorms. Locally heavy rainfall possible in the afternoon. Highs around 88 near the shore to around 73 near 5000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 50 percent.

Thursday Night: Mostly cloudy. Breezy. Scattered showers and slight chance of thunderstorms in the evening, then scattered showers after midnight. Locally heavy rainfall possible in the evening. Lows around 78 near the shore to around 62 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Puna

Tonight: Scattered showers in the evening, then occasional showers after midnight. Lows 69 to 76 near the shore to around 64 at 4000 feet. North winds up to 15 mph. Chance of rain near 100 percent.

Thursday: Cloudy with occasional showers and slight chance of thunderstorms. Locally heavy rainfall possible. Highs around 84 near the shore to around 70 at 4000 feet. East winds up to 15 mph. Chance of rain 90 percent.

Thursday Night: Cloudy. Occasional showers and slight chance of thunderstorms in the evening, then showers likely after midnight. Locally heavy rainfall possible. Lows 68 to 75 near the shore to around 61 at 4000 feet. East winds up to 10 mph. Chance of rain 90 percent.

Waikoloa

Tonight: Breezy. Partly cloudy with isolated showers. Lows around 77 near the shore to around 62 above 4000 feet. East winds up to 20 mph. Gusts up to 40 mph in the evening. Chance of rain 20 percent.

Thursday: Mostly sunny with slight chance of thunderstorms and isolated showers in the morning, then mostly cloudy with showers likely and slight chance of thunderstorms in the afternoon. Locally heavy rainfall possible in the afternoon. Highs 87 to 93 near the shore to 71 to 77 above 4000 feet. North winds up to 10 mph. Chance of rain 60 percent.

Thursday Night: Partly cloudy. Scattered showers and slight chance of thunderstorms in the evening, then scattered showers after midnight. Locally heavy rainfall possible. Lows around 76 near the shore to 58 to 63 above 4000 feet. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Breezy trades expected through the middle of next week. An upper level trough and moisture associated with the remnants of Norbert will fill in across the state from east to west Thursday into Friday, increasing the chances of heavy rain, isolated thunderstorms, and flash flooding, especially for the windward and mauka areas. Drier air will move back in this weekend behind the departing trough. Moisture from the remnants of Tropical Depression 15-E may bring another round of enhanced trade showers around next Tuesday and Wednesday.

Discussion

Afternoon satellite imagery shows an upper level low around 1400 mi north- northeast of the islands with a trough extending southwestward. Isolated light showers continue to move westward with the greatest coverage from Maui northward. Trade winds will continue to strengthen through the afternoon as the upper trough approaches.
The upper level trough will dig southwest tonight into Thursday, pulling in remnant moisture from Norbert. Satellite imagery shows a broad area of precipitable water in excess of 2″ beginning to move into the Big Island, and is forecast to move across the remaining islands tonight into Thursday. Deeper moisture and increasing instability will bring moderate to locally heavy showers and a slight chance of thunderstorms, with the highest threat of thunderstorms across the Big Island Thursday afternoon. Heaviest rain is expected on the windward and mauka areas. With soil moisture likely still high from previous heavy rain events, there is an increased risk of flash flooding where heavier showers and thunderstorms occur.
Moisture will decrease from east to west late Friday through the weekend. There is the potential for another round of increasing moisture from the remnants of tropical depression 15-E moving into around Tuesday to Wednesday of next week. Ensembles show at least a weak low-level wave associated with this moisture, though further aloft only 6% of the ensemble members have some form of troughing while the remainder keep us under a ridge, limiting the potential for heavier showers.

Aviation

Moderate to locally breezy trade winds will strengthen to breezy levels this afternoon and a trough will approach the area from the east. Showers and low clouds associated with that trough will increase with the trade wind flow from east to west starting early tonight for the eastern half of the state, then spread west late tonight into tomorrow morning. More widespread MVFR conditions will be possible as the moisture associated with the trough moves in, especially for windward and mountain areas.
No AIRMETs are currently in effect. There is the possibility for AIRMET Tango during the afternoon once trade winds strengthen. There is also potential for AIRMET SIERRA later today as clouds increase on the windward slopes.

Marine

A broad trough, associated with the remnants of Tropical Storm Norbert, will approach the state from the east tonight, allowing moderate to locally strong northeast trades to hold through tonight. This afternoon ASCAT pass showed borderline Small Craft Advisory (SCA) conditions around Maui County and the Big Island leading to less confidence that SCA conditions will hold as the trough passes over the state Thursday, thus have not extended the SCA at this time. After the trough moves through the state Thursday into Friday, a surface high far northeast of the state could allow moderate to locally strong trades to return over the weekend through the forecast period. Above normal moisture and upper level support will allow isolated thunderstorms with localized heavy rain and gusty outflows to develop over the offshore waters tonight through Saturday.
A series of long to medium period south-southwest to south swells will continue fill tonight. Surf along south facing shores should begin to see more consistent sets tonight into Thursday as build to near average. A reinforcing southerly swell will fill in Friday bumping surf near High Surf Advisory thresholds by this weekend as swells shift more out of a south direction.
Surf along east- facing shores increases today into Thursday as trade winds strengthen and a small, medium- period east swell from the remnants of Norbert arrives. Flat to tiny surf along north facing shores is expected through the forecast period.

Fire weather

Issued at 400 PM HST Wed Sep 16 2026
Fire weather risk should remain low through the remainder of the week due to moderate to breezy winds and increased relative humidity and moisture from the remnants of Norbert. Showers will dramatically increase late tonight through early Friday. Inversion heights will be around 7,500 to 8,500 ft.

HFO Watches/Warnings/Advisories

Flood Watch through late Thursday night for Big Island East, Big Island Interior, Big Island North, Big Island South, Big Island Southeast, Big Island Summits, Central Oahu, East Honolulu, Ewa Plain, Haleakala Summit, Honolulu Metro, Kahoolawe, Kauai East, Kauai Mountains, Kauai North, Kauai South, Kauai Southwest, Kipahulu, Kohala, Kona, Koolau Leeward, Koolau Windward, Lanai Leeward, Lanai Mauka, Lanai South, Lanai Windward, Maui Central Valley North, Maui Central Valley South, Maui Leeward West, Maui Windward West, Molokai Leeward South, Molokai North, Molokai Southeast, Molokai West, Molokai Windward, Niihau, Oahu North Shore, Olomana, South Haleakala, South Maui/Upcountry, Waianae Coast, Waianae Mountains, Windward Haleakala.
Small Craft Advisory until 6 AM HST Thursday for Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters, Maalaea Bay, Pailolo Channel.

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Data Courtesy of NOAA.gov