West Kaua’i

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 69 to 74 near the shore to around 61 above 3000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Thursday: Mostly sunny with isolated showers. Highs 85 to 90 near the shore to around 77 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Thursday Night: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 72 near the shore to around 62 above 3000 feet. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

South Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers. Highs 79 to 88. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 70 to 75. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with numerous showers. Lows 64 to 69 in the valleys to around 59 above 4000 feet. East winds 10 to 20 mph decreasing to up to 20 mph after midnight. Chance of rain 70 percent.

Thursday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 74 to 84 in the valleys to around 66 above 4000 feet. East winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Thursday Night: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous showers after midnight. Lows 64 to 70 in the valleys to around 59 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

North Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 65 to 73. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny in the morning then becoming mostly sunny. Scattered showers. Highs 76 to 88. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Thursday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 65 to 74. East winds 10 to 15 mph. Chance of rain 60 percent.

East Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 64 to 76. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with scattered showers. Highs 73 to 85. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 64 to 76. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

High pressure far northeast of the state will maintain moderate to locally breezy trades through the week. Expect fairly typical summertime weather with clouds and showers favoring windward and mauka areas.

Discussion

A 1032 mb surface high remains centered approximately 1400 miles northeast of the Hawaiian Islands. This is producing moderate to locally breezy trades across the state this afternoon. Satellite imagery continues to shallow bands of moisture embedded in the trades with clouds moving into windward and mauka areas, with radar imagery showing isolated light showers across the area. Expect these fairly typical summertime conditions to continue tonight.
Guidance continues to show high pressure remaining northeast of the state through the week, then drifting north starting on Sunday. Moderate to breezy trades will continue through Saturday, then start to weaken as the high moves further away. With no organized source of moisture upstream of the state expect fairly typically summertime conditions under a dry and stable airmass. Clouds will tend to favor windward and mauka areas with passing showers moving in at times through the forecast period.

Aviation

A breezy and stable trade wind flow will persist during the next couple of days. A narrow and shallow band of moisture will remain focused over the central portion of the island chain into Thursday morning and will produce MVFR ceilings and visibility in SHRA across windward slopes. AIRMET Sierra for mountain obscuration is in effect for windward Maui, Molokai, and Lanai and may need to be expanded to Oahu overnight. Elsewhere, VFR conditions will prevail. Radar data support the continuation of AIRMET Tango for low level turbulence to the lee of terrain.

Marine

Fresh to locally strong trade winds will persist as high pressure lingers far northeast of the state. A Small Craft Advisory (SCA) is now in effect for the typical windy waters around Big Island and Maui County through 6 am HST Friday. Trades may ease slightly around Sunday as the high drifts further away to the north.
A small mid-period south swell will continue through Thursday. A slight boost to the period expected Friday night. Another small, long-period south swell is expected next Sunday night into Monday. Surf along south facing shores will boost along with the arrival of the mentioned swells. Surf along east-facing shores will be rough and choppy due to the breezy trade winds that will persist the rest of the week. A small northwest swell will pass through the islands Sunday night through Monday night.

Fire weather

Moderate to locally breezy trade winds will continue through the week with afternoon relative humidity near summertime normals. Expect typical summertime fire weather conditions into next week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Friday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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