West Kaua’i

Rest Of Tonight: Breezy. Partly cloudy with isolated showers. Lows 68 to 74 near the shore to around 61 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Monday: Mostly sunny in the morning then becoming mostly cloudy. Breezy. Isolated showers. Highs 85 to 90 near the shore to around 76 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Monday Night: Mostly cloudy. Breezy. Isolated showers after midnight. Lows 69 to 74 near the shore to around 62 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

South Kaua’i

Rest Of Tonight: Breezy. Mostly cloudy with scattered showers. Lows 70 to 75. East winds 15 to 20 mph. Chance of rain 50 percent.

Monday: Breezy. Mostly cloudy with scattered showers. Highs 80 to 88. East winds 15 to 20 mph. Chance of rain 50 percent.

Monday Night: Mostly cloudy. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows around 73. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Kaua’i Mountains

Rest Of Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then numerous showers after midnight. Lows 64 to 69 in the valleys to around 59 above 4000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Monday: Breezy. Mostly cloudy with scattered showers. Highs 73 to 84 in the valleys to around 66 above 4000 feet. East winds 10 to 20 mph decreasing to up to 20 mph in the afternoon. Gusts up to 40 mph. Chance of rain 50 percent.

Monday Night: Breezy. Mostly cloudy with scattered showers. Lows 64 to 70 in the valleys to around 59 above 4000 feet. East winds up to 25 mph. Chance of rain 50 percent.

North Kaua’i

Rest Of Tonight: Mostly cloudy with scattered showers. Lows 64 to 74. East winds up to 15 mph. Chance of rain 50 percent.

Monday: Partly sunny with scattered showers. Highs 76 to 88. East winds up to 15 mph. Chance of rain 40 percent.

Monday Night: Mostly cloudy with scattered showers. Lows 65 to 74. East winds up to 15 mph. Chance of rain 30 percent.

East Kaua’i

Rest Of Tonight: Mostly cloudy with scattered showers. Lows 64 to 77. East winds 10 to 15 mph. Chance of rain 50 percent.

Monday: Mostly cloudy with scattered showers. Highs 73 to 85. East winds 10 to 15 mph. Chance of rain 50 percent.

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

Detailed Forecast

Synopsis

Strong trades will focus showers windward and mauka through the week. The strongest winds are expected Monday and Tuesday.

Discussion

High stability prevails as a strong inversion remains established around 6.5kft. Overnight and early morning periods have seen the expansion of stable low clouds as moisture remains trapped beneath the inversion and expect that to be the case again tonight. As a result, showers remain scattered in nature but light in intensity courtesy of strong capping. The Wind Advisory remains in good shape as the typical windier locales within Maui County and the Big Island have performed to expectations today. Expect the next two days to feature more widespread advisory-criteria winds in these areas as the gradient further strengthens. In addition, weak mid-level troughing will enhance mid-level trades likely warranting a Wind Advisory for the Big Island summits Monday night through Tuesday. That potential will be evaluated in future forecast cycles. The inversion then lifts and weakens slightly by Wednesday as a band of deeper trade wind moisture advances through the area bringing a slight uptick in clouds and showers for windward and mauka zones. Combined with slight weakening of governing high pressure, this will help take the edge off of strong trade winds as they weaken slightly for the remainder of the week.

Aviation

Stable and windy trade winds will continue to persist across the state over the next few days. Passing showers will favor windward and mountain areas in the overnight to early morning hours, bringing the potential for brief MVFR conditions. Otherwise, VFR conditions will prevail.
AIRMET Tango remains in effect for moderate low-level turbulence over and downwind of island terrain. This AIRMET will likely persist as strong trade winds remain in the forecast.

Marine

High pressure will remain anchored far north of the main Hawaiian Islands for the next several days, which will support fresh to strong trade winds across the area. As a result, a Small Craft Advisory remains in effect for all Hawaiian coastal waters until 6 PM HST Monday, but this will likely need to be extended for at least some zones as the gusty trades persist. The surface high will move eastward and weaken slightly during the second half of the week, but winds are likely to remain locally breezy in the typical windier channels and waters south of the Big Island throughout much of the next seven days.
South shore surf is expected to slowly decline as a south swell fades through Monday. The next small, long-period south swell is expected to arrive late Tuesday, peaking on Wednesday. This swell may boost south-facing shore surf heights to near summertime averages for the middle of the week. It will then decline through Friday.
Surf along east-facing shores will be rough and choppy in response to the gusty easterly trade winds throughout the next few days.

Fire weather

Marginal fire weather conditions will exist into the middle of the week as trades further strengthen for Monday and Tuesday. The inversion will hold around 6.5kft as the resident airmass trends slightly drier. The KBDI will remain a touch below criteria (600) throughout this time limiting the liklihood of fire weather headlines.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 PM HST Monday for Lanai Mauka, Kahoolawe, Maui Windward West, Maui Leeward West, Kohala, Molokai, Lanai Windward, Lanai Leeward, Lanai South, Maui Central Valley North, Maui Central Valley South, Windward Haleakala, South Haleakala, Big Island South, Big Island Southeast, Big Island North.
Small Craft Advisory until 6 PM HST Monday for all Hawaiian waters,