West Kaua’i

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows around 71 near the shore to around 62 above 3000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tuesday: Partly sunny with scattered showers. Highs 83 to 89 near the shore to around 76 above 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tuesday Night: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 69 to 74 near the shore to around 62 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Tonight: Mostly cloudy. Occasional showers in the evening, then numerous showers after midnight. Lows around 72. Northeast winds 10 to 15 mph. Chance of rain 80 percent.

Tuesday: Partly sunny with scattered showers. Highs 80 to 88. East winds 10 to 15 mph. Chance of rain 50 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows around 73. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Kaua’i Mountains

Tonight: Occasional showers. Lows 64 to 69 in the valleys to around 59 above 4000 feet. East winds up to 10 mph. Chance of rain near 100 percent.

Tuesday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 82 in the valleys to around 66 above 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows 64 to 70 in the valleys to around 59 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

North Kaua’i

Tonight: Mostly cloudy with numerous showers. Lows 65 to 73. Southeast winds up to 15 mph. Chance of rain 70 percent.

Tuesday: Partly sunny with scattered showers. Highs 78 to 86. East winds up to 15 mph. Chance of rain 50 percent.

Tuesday Night: Mostly cloudy with isolated showers. Lows 65 to 73. Southeast winds up to 15 mph increasing to 10 to 15 mph after midnight. Chance of rain 20 percent.

East Kaua’i

Tonight: Numerous showers in the evening, then occasional showers after midnight. Lows 64 to 75. East winds up to 15 mph. Chance of rain near 100 percent.

Tuesday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 73 to 85. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 70 percent.

Tuesday Night: Mostly cloudy with scattered showers. Lows 65 to 76. East winds up to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A trough to the west and a ridge to the northeast will drive moderate to fresh east southeast winds through Tuesday, then strengthen through the end of the week. Winds will focus clouds and showers across windward and mauka areas.

Discussion

A surface trough to the west and a ridge to the northeast will drive moderate to fresh east northeast winds across the state into Tuesday. Incoming clouds and scattered showers will impact windward and mauka areas. Stable, zonal flow aloft will keep showers light this week.
The trough will gradually weaken Wednesday through Friday with high pressure filling in north of the area. Trade winds across the islands will strengthen around midweek as the trough begins to fade. Trade winds will boost further this weekend. The rainfall pattern will follow the typical diurnal trends with higher shower coverage in the overnight to early morning hours, and then less shower activity during the mid morning through afternoon time period, and continue to favor windward and mauka areas through the forecast period.

Aviation

A trough to the northwest of the state will interact with the high to the far northeast, bringing light to moderate trades to the Hawaiian Islands through Tuesday. A hybrid sea breeze and trade wind pattern will persist over each island, with daytime sea breezes developing along terrain sheltered western mountain slopes. Downstream of each island, weak convergence will also bring the potential for more showers this afternoon and again tomorrow as the steering flow maintains a southeasterly component. Otherwise, brief passing showers are possible over windward and mountain areas with the trades, favoring the overnight to early morning hours. Outside of any brief showers, VFR conditions will prevail through Tuesday.
No AIRMETs are currently in effect this afternoon.

Marine

High pressure will remain centered far north-northeast of Hawaii over the next several days. A developing trough northwest of the state will briefly cause trade winds to veer out of the east-southeast into Tuesday. As the trough weakens and moves away later Tuesday, trades will strengthen into the moderate to locally strong range for the second half of this week. Small Craft Advisory conditions could return to the typical windy areas around Maui County and the Big Island as early as Wednesday. As the ridge strengthens, widespread fresh to strong trade winds are possible this weekend.
The current south-southwest (200 degrees) swell will continue to decline over the next couple of days. A small, moderate-period south- southwest swell (210 degrees) is possible Friday into the weekend.
Surf along east facing shores will remain moderate as the short- period north swell holds through Monday. Strengthening trade winds will gradually increase east shore waves during the second half of the week and through the weekend.
Pulses of small short-period energy out of the north will continue to move through Tuesday through the middle of the week to keep the north shore surf from going completely flat.

HFO Watches/Warnings/Advisories

None.

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