West Kaua’i

Tonight: Mostly clear. Isolated showers in the evening. Lows around 69 near the shore to around 58 above 3000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Wednesday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 80 to 86 near the shore to around 69 above 3000 feet. Light winds. Chance of rain 40 percent.

Wednesday Night: Mostly clear. Lows around 68 near the shore to around 57 above 3000 feet. Light winds.

South Kaua’i

Tonight: Partly cloudy. Isolated showers after midnight. Lows around 68. East winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Wednesday: Mostly sunny with isolated showers. Highs 77 to 84. Light winds becoming east around 10 mph in the afternoon. Chance of rain 20 percent.

Wednesday Night: Partly cloudy. Isolated showers in the evening. Lows around 68. Northeast winds around 10 mph. Chance of rain 20 percent.

Kaua’i Mountains

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 61 to 67 in the valleys to around 57 above 4000 feet. South winds up to 10 mph in the evening becoming light. Chance of rain 40 percent.

Wednesday: Partly sunny with scattered showers. Highs 71 to 81 in the valleys to around 63 above 4000 feet. Light winds. Chance of rain 50 percent.

Wednesday Night: Partly cloudy. Scattered showers in the evening, then isolated showers after midnight. Lows 60 to 66 in the valleys to around 56 above 4000 feet. East winds up to 10 mph. Chance of rain 40 percent.

North Kaua’i

Tonight: Partly cloudy with isolated showers. Lows 62 to 69. Southeast winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Wednesday: Mostly sunny with isolated showers. Highs 74 to 81. Southeast winds up to 10 mph shifting to the east in the afternoon. Chance of rain 20 percent.

Wednesday Night: Partly cloudy with isolated showers. Lows 61 to 69. East winds up to 10 mph. Chance of rain 20 percent.

East Kaua’i

Tonight: Partly cloudy with isolated showers. Lows 62 to 71. Southwest winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Wednesday: Mostly sunny with isolated showers. Highs 73 to 84. Light winds becoming east around 10 mph in the afternoon. Chance of rain 20 percent.

Wednesday Night: Partly cloudy with isolated showers. Lows 61 to 71. East winds around 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Light to moderate east to east-southeast trade winds will persist through the rest of the week with light and variable winds possible over the weekend. Some scattered showers will be possible through Wednesday with a drier air mass moving in Thursday, which should limit shower activity through the weekend.

Discussion

This afternoon's satellite and radar imagery shows scattered showers over windward Big Island and the kona slopes of the Big Island. These showers have been mainly producing light rainfall amounts and is expected to decrease this evening. Another pocket of moisture is seen on satellite roughly 100 miles east of the Big Island, which could bring another round of some light showers to windward Big Island late tonight into Wednesday morning. Otherwise, mostly dry conditions are expected tonight with a few light showers possible over windward and mountain areas.
Trade winds have returned across many areas today and we will continue to see moderate easterly trade winds over the eastern half of the state, and a hybrid trade wind/sea breeze pattern over the western half of the state through the rest of the work week. Winds will be light and out of the east-southeast over the western half of the state, which should allow for afternoon sea breezes to develop across select leeward areas. This should allow for some afternoon cloud build ups with a few light sprinkles possible over interior and leeward areas.
From Wednesday night, an upper level ridge will build over the state and persist through the weekend, which will lead to stable and mostly dry conditions. Some pockets of low level moisture may move in from time to time, but any shower activity should remain brief and light in intensity. Over the weekend, a front passing north of the state will cause the ridge to shift closer to the state. Stable conditions will continue to persist, but with lighter winds over the weekend across the state.

Aviation

A surface ridge will move to a position just N of Kauai overnight. This will lead to light SE winds over Kauai and Oahu, and light to moderate E winds over Maui and Hawaii Counties, which will deliver low clouds and limited showers to windward slopes, producing ISOL MVFR CIGs. Land and sea breezes will be likely over sheltered leeward areas, leading to clearing at night and some afternoon clouds over leeward and interior areas. VFR conditions will prevail, and windward cloud coverage is not expected to become sufficiently extensive to warrant an AIRMET for mountain obscuration.

Marine

Light to moderate east to east southeast flow forecast through the remainder of this week as a ridge of high pressure becomes more established north of the state.
A large west-northwest swell will be reinforced overnight into Wednesday followed by another swell Thursday. A High Surf Advisory (HSA) is in effect along exposed north and west facing beaches of most islands through 6 PM HST Wednesday. Thursday's swell will be of similar size likely producing advisory level surf for the same areas, briefly falling below advisory levels between them.
Small surf is expected along east facing shores this week as trades remain light. A slight increase is possible through the rest of the week as trades become more established. Surf along south facing shores should see a small boost on Wednesday as a small south swell fills in through the second half of the week.
A Small Craft Advisory (SCA) for hazardous seas for waters exposed to these large swells goes through 6 AM HST Wednesday.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST Wednesday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kona, Kohala, Kauai North, Molokai Windward, Molokai North, Molokai West, Windward Haleakala, Big Island South.
Small Craft Advisory until 6 AM HST Wednesday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters.

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