West Kaua’i

Tonight: Mostly clear. Lows around 66 near the shore to around 55 above 3000 feet. Light winds becoming northeast up to 10 mph after midnight.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs 79 to 85 near the shore to around 70 above 3000 feet. East winds up to 15 mph shifting to the south in the afternoon. Chance of rain 20 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows around 68 near the shore to around 58 above 3000 feet. South winds up to 10 mph shifting to the northeast after midnight. Chance of rain 50 percent.

South Kaua’i

Tonight: Mostly clear. Lows around 66. Light winds.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs 77 to 84. Southwest winds 10 to 15 mph. Chance of rain 20 percent.

Thursday Night: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows around 68. West winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Kaua’i Mountains

Tonight: Mostly clear. Lows 56 to 65 in the valleys to around 54 above 4000 feet. Light winds.

Thursday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 74 to 82 in the valleys to around 64 above 4000 feet. Southwest winds up to 20 mph. Chance of rain 20 percent.

Thursday Night: Breezy. Partly cloudy with scattered showers. Lows 58 to 67 in the valleys to around 57 above 4000 feet. Southwest winds up to 20 mph. Chance of rain 50 percent.

North Kaua’i

Tonight: Mostly clear. Lows 58 to 67. Light winds becoming south up to 10 mph after midnight.

Thursday: Sunny and breezy. Highs 74 to 83. South winds up to 20 mph.

Thursday Night: Breezy. Partly cloudy with isolated showers. Lows 61 to 68. South winds up to 20 mph. Chance of rain 20 percent.

East Kaua’i

Tonight: Mostly clear. Lows 58 to 68. Light winds becoming southwest up to 10 mph after midnight.

Thursday: Sunny and breezy. Isolated showers in the afternoon. Highs 73 to 84. Southwest winds 10 to 25 mph. Chance of rain 20 percent.

Thursday Night: Breezy. Partly cloudy with scattered showers. Lows 61 to 71. Southwest winds up to 25 mph shifting to the west up to 15 mph after midnight. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Light southeast flow will veer southwesterly by Thursday as a front approaches. The front will dissipate over Kauai Friday while deeper tropical moisture tracks in from the southeast mainly impacting Big Island Friday night into Saturday moving up to Kauai and Oahu Saturday night and Sunday. Another front will keep unsettled weather for the western half into early next week.

Discussion

Light southeast wind flow across the state is driven by a weak ridge east northeast of the area. The light flow has allowed for sea breezes become more dominant. Land breezes should suppress clouds and showers tonight.
By Thursday, winds will strengthen out of the south to southwest, particularly for Kauai and Oahu, as a cold front approaches from the west. No significant precipitation expected through Thursday evening. The front will stall near Kauai Friday morning with an expected boost in showers through the day. Meanwhile, an area of enhanced tropical moisture will move in the brief trade wind flow to the east and bring clouds and showers over the windward and southeast portions of the Big Island Friday night into Saturday. Winds will quickly shift back southeasterly as the next front approaches from the west, and the enhanced moisture will move on a northwesterly track towards Kauai and Oahu Saturday night into early next week where it eventually merges with the next front. This setup could produce some localized heavy rain, but still a lot of uncertainty in the forecast on the setup for this event.

Aviation

Light ESE low-level flow will persist into tonight, with VFR conditions prevailing. The best chance for clouds and brief showers will be over interior and leeward sections through the late afternoon hours, then over windward and mauka locations late tonight through early Thursday. The low-level flow will gradually veer out of the south to south-southwest through the day Thursday as a front approaches from the west.
AIRMETs are not anticipated through the 24-h period.

Marine

Light to moderate southeasterlies persist through the weekend with the exception of Thursday and Friday when winds veer to southerly in response to a low tracking well north of the area. ESE flow over the weekend may reach the Small Craft Advisory threshold in the typical windy areas over the eastern end of the state.
Offshore NDBC buoys 51001 and 51101 still hovering around 9 to 11 feet, 14 to 16 seconds this afternoon which will maintain elevated surf well into tonight. The High Surf Advisory remains in effect as is. Surf will steadily decline during Thursday allowing the High Surf Advisory to expire. This will be followed by another NW (300-310) swell that will quickly build during Friday, peak above the High Surf Warning thresholds for N and W facing shores late Friday, and then subside through the weekend. A Small Craft Advisory for seas at/above 10 feet will also be needed during this time.
Surf along east and south facing shores will remain small through the week, though a modest uptick in waves on the south shore is possible later today into the weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 AM HST Thursday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.
Small Craft Advisory until 6 PM HST this evening for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters.

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