West Kaua’i

Tonight: Mostly cloudy. Scattered showers early in the evening. Haze through the night. Lows around 67 near the shore to around 58 above 3000 feet. Light winds. Chance of rain 30 percent.

Sunday: Mostly cloudy. Haze through the day. Isolated showers in the afternoon. Highs 79 to 87 near the shore to around 73 above 3000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Sunday Night: Mostly cloudy. Isolated showers early in the evening, then scattered showers in the late evening and overnight. Haze through the night. Lows 66 to 71 near the shore to around 59 above 3000 feet. East winds up to 15 mph. Chance of rain 30 percent.

South Kaua’i

Tonight: Mostly cloudy with isolated showers. Haze. Lows around 68. Northeast winds around 10 mph. Chance of rain 20 percent.

Sunday: Partly sunny with isolated showers. Haze. Highs 79 to 86. East winds around 10 mph shifting to the southeast in the afternoon. Chance of rain 20 percent.

Sunday Night: Mostly cloudy with scattered showers. Haze. Lows around 70. Light winds becoming northeast up to 10 mph after midnight. Chance of rain 30 percent.

Kaua’i Mountains

Tonight: Mostly cloudy. Scattered showers early in the evening. Haze through the night. Lows 58 to 67 in the valleys to around 56 above 4000 feet. Light winds. Chance of rain 30 percent.

Sunday: Mostly cloudy. Haze through the day. Scattered showers in the afternoon. Highs 74 to 80 in the valleys to around 65 above 4000 feet. Light winds. Chance of rain 30 percent.

Sunday Night: Mostly cloudy. Scattered showers early in the evening, then isolated showers in the late evening and overnight. Haze through the night. Lows 60 to 69 in the valleys to around 58 above 4000 feet. Light winds becoming south up to 15 mph after midnight. Chance of rain 30 percent.

North Kaua’i

Tonight: Mostly cloudy with isolated showers. Haze. Lows 61 to 68. Southeast winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Sunday: Mostly cloudy with isolated showers. Haze. Highs 75 to 82. Southeast winds up to 10 mph. Chance of rain 20 percent.

Sunday Night: Mostly cloudy with isolated showers. Haze. Lows 62 to 70. South winds up to 10 mph. Chance of rain 20 percent.

East Kaua’i

Tonight: Mostly cloudy with isolated showers. Haze. Lows 61 to 71. Light winds. Chance of rain 20 percent.

Sunday: Mostly cloudy with isolated showers. Haze. Highs 73 to 85. Southeast winds up to 10 mph. Chance of rain 20 percent.

Sunday Night: Mostly cloudy. Isolated showers early in the evening, then scattered showers in the late evening and overnight. Haze through the night. Lows 63 to 73. Southwest winds up to 10 mph. Chance of rain 30 percent.

Detailed Forecast

Synopsis

Light winds will prevail through the weekend, with daytime sea breezes and overnight land breezes common across the state. A cold front west of the state will bring moderate south to southeast winds to the area Monday through Wednesday. Winds will ease from west to east Thursday, with the front arrival potentially bringing a chance for significant rainfall to the western islands Friday.

Discussion

A stationary front lies about 300 miles north of Kauai this afternoon. A deep low is positioned far to the west northwest with an associated front west of the area. Meanwhile, high pressure is centered to the east northeast with the associated ridge over the islands. Visible satellite imagery shows cloud build ups over the islands due to the sea breezes.
Light winds will prevail with nighttime land and daytime sea breezes common across much of the state through the rest of the weekend. The front to the west will edge closer to the state early next week, while the high pressure to the northeast edges closer to the islands. As a result, moderate southeasterly winds should prevail over the eastern end of the state, while moderate southerly winds hold over the western islands from Monday through Wednesday. A front appears to approach from the northwest toward the end of next week, which should gradually ease winds to light levels from west to east by Thursday.
As for the remaining weather details, not too much change to the overall weather pattern is expected through Monday. Mid-level ridging will hold over the state, keeping showers limited and near the coast at night, with daytime heating driven shower development over the island interiors each afternoon. Ridging aloft appears to break down a bit Monday night and Tuesday, with increasing southerly flow bringing some deeper moisture northward into the western islands. As a result, the expectation is for an increase in shower coverage, particularly over the western islands. Easing winds Thursday should result in showers favoring areas near the coast at night and over interior and leeward areas each afternoon. A cold front could push into the western islands Friday, bringing a better shot for some more significant rainfall.

Aviation

A stable and gentle to locally moderate east to southeast flow will continue to produce predominantly VFR conditions through Sunday. A weak surface ridge just north of Kauai will drive gentle to locally moderate easterly winds around the Big Island and Maui while weaker east to southeast winds persist elsewhere. Daytime sea breezes and overnight land breezes will overpower the background flow, leading to interior clouds and spotty showers during the afternoon hours. Due to the stable conditions and lack of significant moisture, only isolated MVFR conditions are expected, with no AIRMETs anticipated. Overnight land breezes will lead to diminished clouds and shower chances.

Marine

A surface ridge lingering over the islands will keep winds light and variable through Sunday with local land/sea breezes. Winds will then shift further out of the south and strengthen to moderate to locally breezy levels from Monday through the middle of next week as a low pressure system and a front northwest of the state drift east towards the Hawaiian islands. The stronger southerly winds will likely be observed over the western end of the state. The front associated with this low could approach the western end of the coastal waters during the later half of next week.
Surf along exposed north and east facing shores will persist through the weekend due to a small north-northeast swell moving through. Guidance shows this source slowly fading tomorrow through Monday, with a north and west swell arriving around Tuesday. The north swell may linger into the second half of next week. In the long range outlook, a large north swell is possible towards the end of next week depending on the track and intensity of the current low to the northwest, stay tuned.
Surf along south facing shores will remain up tonight, with a return to seasonable levels Sunday into early next week as a small south swell moves through.

HFO Watches/Warnings/Advisories

None.

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