West Kaua’i

Tonight: Partly cloudy with isolated showers. Lows around 67 near the shore to around 57 above 3000 feet. Northeast winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 20 percent.

Wednesday: Breezy. Mostly sunny with isolated showers. Highs 78 to 85 near the shore to around 69 above 3000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Wednesday Night: Breezy. Partly cloudy with isolated showers in the evening, then mostly cloudy with numerous showers after midnight. Lows 65 to 70 near the shore to around 58 above 3000 feet. Northeast winds up to 20 mph. Chance of rain 70 percent.

South Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 67. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Wednesday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 76 to 84. Northeast winds 15 to 25 mph. Chance of rain 70 percent.

Wednesday Night: Mostly cloudy. Breezy. Scattered showers in the evening, then occasional showers after midnight. Lows around 68. Northeast winds 15 to 25 mph. Chance of rain 90 percent.

Kaua’i Mountains

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous showers after midnight. Lows 58 to 66 in the valleys to around 55 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 70 percent.

Wednesday: Mostly cloudy. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 68 to 75 in the valleys to around 60 above 4000 feet. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Wednesday Night: Mostly cloudy. Breezy. Numerous showers in the evening, then occasional showers after midnight. Lows 58 to 67 in the valleys to around 56 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 90 percent.

North Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 60 to 68. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with scattered showers. Highs 71 to 80. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday Night: Mostly cloudy. Breezy. Scattered showers in the evening, then occasional showers after midnight. Lows 61 to 68. East winds 10 to 20 mph. Chance of rain 90 percent.

East Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 60 to 71. North winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Breezy. Partly sunny with scattered showers. Highs 68 to 81. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Wednesday Night: Mostly cloudy. Breezy. Scattered showers in the evening, then occasional showers after midnight. Lows 62 to 71. Northeast winds 10 to 20 mph. Chance of rain 90 percent.

Detailed Forecast

Synopsis

Breezy trades continue through the weekend with clouds and showers focused over windward and mauka areas. A brief period of wet trades is anticipated late Wednesday through Thursday.

Discussion

Regional satellite indicates a band of shallow moisture associated with a remnant frontal zone anchored over the Big Island where showers have been widespread through today, including over leeward zones. The remainder of the forecast area remains on the drier side with little upstream moisture of note. Consensus exists among the medium range guidance that Wednesday night through the end of the week will feature aggressively building high pressure as a 1035mb high pressure tracks along roughly 35N. The convergent lead edge of the building high will provide a boost to existing shower activity as the plume of moisture presently anchored over the Big Island is ushered westward over the remainder of the island chain. As such, a period of wet trades is anticipated Wednesday night through Thursday. Moisture content within the trades then decreases to more typical levels as breezy trades continue through the weekend.

Aviation

Trades weaken slightly through tonight then strengthen again during Wednesday, especially over the western portion of the state. Trades will deliver clouds and showers to windward and mauka sections during this time, particularly those of Maui County and the Big Island. Isolated pockets of MVFR can be expected within any heavier showers with more persistent MVFR for Windward Big Island, especially through the first half of tonight. VFR prevails elsewhere.
AIRMET Sierra for mountain obscuration remains in effect for Windward Big Island.

Marine

The high pressure ridge north of the islands will maintain moderate trades tonight then strengthen to fresh to locally strong levels by Wednesday night, which will continue through early next week.
The current north swell will continue to decline through Wednesday with a small north reinforcement Thursday and Friday. Small surf heights expected for the weekend.
A moderate period south swell will keep surf heights slightly elevated, but below advisory levels along south facing shores through Thursday before tapering off through the rest of the week.
The current long period south swell will peak today near or slightly above the summer average heights. This swell will trend lower on Wednesday and surf will then return to small background levels from Friday into the weekend. Rough, choppy surf will continue along east facing shores as trade wind speeds remain elevated.

HFO Watches/Warnings/Advisories

None.

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