Photo Credit: Braden Jarvis

West Kaua’i

Today: Mostly sunny. Isolated showers in the afternoon. Highs around 90 near the shore to around 76 above 3000 feet. Northeast winds up to 15 mph shifting to the west in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy. Lows around 71 near the shore to around 61 above 3000 feet. Light winds.

Thursday: Mostly sunny in the morning then becoming partly sunny. Highs around 90 near the shore to around 76 above 3000 feet. Light winds becoming southwest up to 10 mph in the afternoon.

South Kaua’i

Today: Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 81 to 88. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening, then mostly cloudy with scattered showers after midnight. Lows around 71. Northeast winds 10 to 15 mph. Chance of rain 30 percent.

Thursday: Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 82 to 89. East winds around 10 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 75 to 88 in the valleys to 63 to 69 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 66 to 71 in the valleys to around 58 above 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 76 to 88 in the valleys to 64 to 70 above 4000 feet. Light winds becoming east up to 10 mph in the afternoon. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 78 to 90. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 65 to 74. East winds up to 10 mph in the evening becoming light. Chance of rain 40 percent.

Thursday: Partly sunny with isolated showers. Highs 79 to 90. East winds up to 10 mph. Chance of rain 20 percent.

East Kaua’i

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 75 to 87. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 65 to 76. North winds up to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny with isolated showers. Highs 76 to 87. North winds up to 10 mph shifting to the east in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A low pressure system developing far northeast of the state will shift a broad ridge of high pressure just north of the state through the rest of the week. This shift will result in gentle to breezy trade winds through the rest of the week. In addition, showers will be limited along windward and mauka areas as a drier and more stable airmass moves over the state and persists through the week.

Discussion

A developing low pressure system remains 1100 miles northeast of the state, while a broad ridge of high pressure extends just south of the low across the Central and Eastern Pacific. This weak ridge is producing gentle to breezy trades across the state. Radar and satellite imagery show minimal low level clouds and showers focusing along windward and mauka areas, and some clouds along the Kona coast of the Big Island. Most rain gauge observations came in less than .02 of an inch in the past 6 hours, except for some gauge reporting under a .20 of an inch along the Kona slopes of the Big Island. High cirrus clouds have thinned out over night, but still remain prevalent across the state.
Little change in the clouds and showers is expected over the next day or so. Mid- level ridging should hold into early next week keeping low level clouds and light showers focused mainly along windward and mauka areas with few showers spilling over to leeward areas during the overnight and early morning hours. The Kona slopes of the Big Island will see some clouds and showers build in the afternoon as seabreezes kick in then push offshore overnight with the land breeze. An area of enhanced moisture may move over the state Friday night into Saturday from east to west adding an uptick in clouds and showers to windward areas. High cirrus clouds are expected to remain through the rest of the week.
The gentle to breezy trade winds may further ease to light and variable for the western half of the state Thursday into Friday as the low broadens far north of the state and the weak ridge sags south just north state. Breezy to locally windy trade winds my gradually return over the weekend into early next week as the low shifts far north of the state, allowing the ridge to strengthen northeast of the state.

Aviation

Moderate trade winds will continue during the next 24 hours. Mostly dry conditions will prevail with light showers confined primarily to windward and mauka areas.
No AIRMETs are currently in effect.

Marine

Trade winds will remain gentle to locally fresh over the next couple of days as a broad area of low pressure develops far northeast of the state and a ridge to the north slowly drifts southward and stall. The trade winds will continue to gradually decrease through Friday. Winds look to increase over the weekend to moderate to locally strong levels as the ridge to the north looks to build back over the islands.
Background energy from the south-southwest swells (200 degrees) will continue to provide small surf for south facing shores today. A compact storm force low tracked eastward along 25S to 30S between 170W and 150W this past weekend. This storm should produce a moderate south swell with long period forerunners filling in locally tonight. This swell will continue to build through Thursday and peak Friday into Saturday morning before slowly declining over the weekend. Surf heights at the peak of the swell looks to be just below High Surf Advisory criteria of 10 feet.
Surf along east facing shores will slowly decline by the end of the week as trade winds decline. Tiny background swell energy from the west- northwest will continue to linger through today. In the long range, a small out of season north- northwest swell is possible around Monday of next week.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov