Hilo

Tonight: Mostly cloudy. Numerous showers in the evening, then scattered showers after midnight. Lows 63 to 70 near the shore to 53 to 59 at 4000 feet. West winds up to 10 mph. Chance of rain 70 percent.

Thursday: Cloudy with frequent showers. Highs 78 to 85 near the shore to around 67 at 4000 feet. East winds 10 to 15 mph decreasing to up to 15 mph in the afternoon. Chance of rain 90 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows 65 to 71 near the shore to 54 to 60 at 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Kona

Tonight: Mostly clear. Lows around 73 near the shore to 47 to 53 near 5000 feet. Light winds.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs 85 to 90 near the shore to around 69 near 5000 feet. Light winds becoming northwest up to 10 mph in the afternoon. Chance of rain 20 percent.

Thursday Night: Partly cloudy. Lows around 74 near the shore to 49 to 55 near 5000 feet. Northeast winds up to 10 mph.

Waimea

Tonight: Breezy. Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 63 to 72 near the shore to 55 to 62 near 3000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers. Highs 65 to 85. East winds 10 to 25 mph. Chance of rain 50 percent.

Thursday Night: Breezy. Partly cloudy with isolated showers. Lows 65 to 73 near the shore to 57 to 64 near 3000 feet. East winds 10 to 25 mph shifting to the southeast after midnight. Chance of rain 20 percent.

Kohala

Tonight: Breezy. Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 63 to 72 near the shore to 55 to 62 near 3000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers. Highs 65 to 85. East winds 10 to 25 mph. Chance of rain 50 percent.

Thursday Night: Breezy. Partly cloudy with isolated showers. Lows 65 to 73 near the shore to 57 to 64 near 3000 feet. East winds 10 to 25 mph shifting to the southeast after midnight. Chance of rain 20 percent.

South Big Island

Tonight: Partly cloudy. Breezy. Lows around 75 near the shore to around 52 near 5000 feet. Northeast winds 10 to 25 mph.

Thursday: Breezy. Mostly sunny with isolated showers. Highs around 87 near the shore to around 69 near 5000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Thursday Night: Mostly clear. Breezy. Lows around 75 near the shore to around 53 near 5000 feet. East winds 10 to 20 mph.

Puna

Tonight: Mostly cloudy. Numerous showers in the evening, then scattered showers after midnight. Lows 63 to 70 near the shore to 53 to 59 at 4000 feet. West winds up to 10 mph. Chance of rain 70 percent.

Thursday: Cloudy with frequent showers. Highs 78 to 85 near the shore to around 67 at 4000 feet. East winds 10 to 15 mph decreasing to up to 15 mph in the afternoon. Chance of rain 90 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows 65 to 71 near the shore to 54 to 60 at 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Waikoloa

Tonight: Mostly clear. Breezy. Lows around 74 near the shore to 51 to 56 above 4000 feet. Southeast winds up to 20 mph.

Thursday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 85 to 91 near the shore to 68 to 74 above 4000 feet. North winds up to 20 mph. Chance of rain 20 percent.

Thursday Night: Mostly clear. Breezy. Lows around 75 near the shore to 53 to 58 above 4000 feet. East winds up to 20 mph.

Detailed Forecast

Update

Relative humidities have recovered to above 50 percent at PHNL and sustained winds are dropping below 20 mph. Since the threat for elevated fire weather concerns is diminishing, the Red Flag Warning has been cancelled. With a plume of moisture expected to move up the island chain tonight through Friday along with weakening trades, additional Red Flag Warnings are not anticipated to be needed over the next couple of days. See below for the previous forecast discussion.

Synopsis

Breezy to locally strong trade winds and dry and stable conditions will continue into the evening hours. Showers will increase and winds will taper off tonight through Friday night as a trough and plume of moisture moves through. Then drier conditions are expected this weekend along with strengthening trade winds.

Aviation

Breezy easterly trade winds will prevail through tonight, with a few low clouds and showers passing over windward and mountain areas. Trade winds are expected to weaken slightly tomorrow, and a slight increase in moisture could bring a small uptick in low clouds and showers for windward Big Island and Maui. Predominantly VFR conditions are expected.
AIRMET Tango remains in effect for moderate low-level turbulence over and downwind of the island terrain. This AIRMET will likely be needed through this evening and could be canceled tomorrow morning as trade wind speeds decrease.

Marine

A surface high pressure ridge north of the state will continue to bring fresh to locally strong trade winds through tonight and allow the Small Craft Advisory (SCA) for the central and eastern waters to remain intact. By Thursday morning, an approaching cold front will push the aforementioned ridge eastward. As trades weaken in response, the SCA will likely be scaled back to just the typical windier channels around the Big Island and Maui. Trades will continue to weaken late Thursday through Saturday.
A 4 to 5 foot, NNW (350), medium period swell was noted on both Hanalei and Waimea nearshore buoys this afternoon. This swell will slowly decrease tonight, with surf remaining below advisory surf height thresholds. Surf along west facing shores remains slightly elevated with wrap around north swell energy lingering into Thursday.
Surf heights along east shores will remain elevated and choppy tonight in response to short period trade wind swell over and upstream of the islands, but then then decline on Thursday as trade wind speeds weaken. Expect tiny south shore surf through the end of the week due to small background swells.
A full moon will bring elevated high tides over the next several days and a coastal flood statement may become warranted.

Prev discussion

/ISSUED 341 PM HST Wed Oct 16 2024/
Broad ridging north and northeast of the islands will continue to produce breezy to locally strong trade winds across the islands through late this afternoon. These stronger winds combined with a drier airmass moving over the islands will maintain fire weather concerns through the afternoon. See the Fire Weather section below for details. Otherwise, with a relatively dry and stable trade wind pattern in place as evidenced in this afternoon's upper air soundings, limited clouds and isolated showers will favor windward portions of the islands through the afternoon.
An upper level low setting up just east-northeast of the state will swing a mid level trough (best seen at 700 mb) east to west across the island chain beginning this evening. This trough and an accompanying plume of moisture will move over windward and southeast Big Island tonight, then gradually spread westward and bring an increase in clouds and showers through Friday. The proximity of the upper level low may also enhance the incoming showers. Trade winds will weaken to become moderate Thursday through Friday as a cold front to the north displaces the ridge further to the northeast and a low pressure system approaches from the far northwest…effectively weakening the local pressure gradient. With this lighter wind pattern, localized sea breezes will bring interior clouds across terrain-sheltered leeward areas Thursday and Friday afternoons before the trade winds re- strengthen this weekend as the ridge builds to the north. Drier air will filter in behind the trough, reducing the rain chances this weekend. Then batches of moisture being brought in on the trades will periodically increase windward and mauka showers through mid week.
AVIATION… Breezy easterly trade winds will prevail through tonight, with a few low clouds and showers passing over windward and mountain areas. Trade winds are expected to weaken slightly tomorrow, and a slight increase in moisture could bring a small uptick in low clouds and showers for windward Big Island and Maui. Predominantly VFR conditions are expected.
AIRMET Tango remains in effect for moderate low-level turbulence over and downwind of the island terrain. This AIRMET will likely be needed through this evening and could be canceled tomorrow morning as trade wind speeds decrease.
MARINE… A surface high pressure ridge north of the state will continue to bring fresh to locally strong trade winds through tonight and allow the Small Craft Advisory (SCA) for the central and eastern waters to remain intact. By Thursday morning, an approaching cold front will push the aforementioned ridge eastward. As trades weaken in response, the SCA will likely be scaled back to just the typical windier channels around the Big Island and Maui. Trades will continue to weaken late Thursday through Saturday.
A 4 to 5 foot, NNW (350), medium period swell was noted on both Hanalei and Waimea nearshore buoys this afternoon. This swell will slowly decrease tonight, with surf remaining below advisory surf height thresholds. Surf along west facing shores remains slightly elevated with wrap around north swell energy lingering into Thursday.
Surf heights along east shores will remain elevated and choppy tonight in response to short period trade wind swell over and upstream of the islands, but then then decline on Thursday as trade wind speeds weaken. Expect tiny south shore surf through the end of the week due to small background swells.
A full moon will bring elevated high tides over the next several days and a coastal flood statement may become warranted.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Thursday for Oahu Leeward Waters, Kaiwi Channel, Maui County Windward Waters, Maui County Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Windward Waters, Big Island Leeward Waters, Big Island Southeast Waters.

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Data Courtesy of NOAA.gov