Photo Credit: Jason Weingardt

West Kaua’i

Today: Breezy. Mostly sunny with scattered showers early in the morning, then partly sunny with isolated showers in the late morning and afternoon. Highs around 88 near the shore to around 76 above 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with isolated showers. Lows 71 to 76 near the shore to around 62 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Tuesday: Mostly cloudy with isolated showers. Highs around 89 near the shore to around 77 above 3000 feet. East winds up to 15 mph. Chance of rain 20 percent.

South Kaua’i

Today: Breezy. Partly sunny with scattered showers. Highs around 85. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 69 to 75. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Tuesday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 86. East winds 10 to 15 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Mostly cloudy. Frequent showers early in the morning, then scattered showers in the late morning and afternoon. Highs 75 to 82 in the valleys to around 66 above 4000 feet. East winds up to 15 mph. Chance of rain 80 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 62 to 67 in the valleys to around 57 above 4000 feet. East winds up to 15 mph. Chance of rain 70 percent.

Tuesday: Mostly cloudy. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 76 to 83 in the valleys to around 67 above 4000 feet. East winds up to 20 mph. Chance of rain 70 percent.

North Kaua’i

Today: Partly sunny. Numerous showers early in the morning, then scattered showers in the late morning and afternoon. Highs 78 to 87. Southeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 75. Southeast winds up to 15 mph becoming around 10 mph after midnight. Chance of rain 50 percent.

Tuesday: Mostly cloudy with scattered showers. Highs 79 to 88. Southeast winds 10 to 15 mph shifting to the east in the afternoon. Chance of rain 50 percent.

East Kaua’i

Today: Mostly cloudy. Numerous showers early in the morning, then scattered showers in the late morning and afternoon. Highs 78 to 86. East winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 63 to 77. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tuesday: Mostly cloudy with scattered showers. Highs 79 to 87. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Moderate to breezy easterly trade winds will continue through the week, with clouds and showers favoring windward and mauka locations overnight through the morning periods as pockets of moisture move through. The trades may ease slightly next weekend as the ridge to the north weakens.

Discussion

Guidance remains in agreement and shows a typical easterly trade wind pattern persisting through the week as deep troughing remains off to the west and the surface ridge positioned to the north. Clouds and showers will favor windward and mauka locations, with the best chances being overnight through the early morning hours as pockets of moisture move through. Although a few showers will make it into leeward areas (inversions around 8-10 kft), rainfall accumulations should remain light. Simulated satellite imagery does depict a band of high clouds spreading over the state later today from west to east, then lingering through the first half of the week due to the upper trough/low off to the west. Any high clouds that move in should clear out through the second half of the week as upper heights rise and the upper flow shifts. For the extended forecast, guidance shows a weakness forming in the ridge to the north, which could lead to our trades easing slightly next weekend if it materializes.

Aviation

Surface high pressure north of the state will continue to bring moderate to locally breezy trades the islands through the forecast period. An inversion height of 8 to 10 kft will allow for scattered moderate to occasionally heavier showers along windward locations. In addition, isolated activity may push over the elevated terrain and affect leeward areas. Brief periods of MVFR ceilings and visibility may accompany some of the more robust showers this morning.
AIRMET SIERRA remains in effect above 2500 feet for north through east sections of Oahu and the Big Island for tempo mountain obscuration from clouds and showers.

Marine

A high far northeast of the main Hawaiian Islands will continue to drive moderate to strong trade winds across local waters. A Small Craft Advisory (SCA) remains in effect through Wednesday afternoon for the typical windier waters around Maui and the Big Island. This SCA will likely be extended through the end of the week.
A small, medium to long period south (170-180 degree) swell will slowly decrease today and Tuesday. Another long period background south swell will arrive late Tuesday through Wednesday, boosting surf heights slightly along south facing shores. Persistent moderate trade winds will keep small east chop into next week. No significant swells are expected to reach north and west facing shores for the next seven days.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov