Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny. Highs around 90 near the shore to around 76 above 3000 feet. Southwest winds up to 10 mph.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Lows around 72 near the shore to around 61 above 3000 feet. Light winds.

Friday: Mostly sunny. Isolated showers in the afternoon. Highs around 91 near the shore to around 76 above 3000 feet. South winds up to 10 mph. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny with isolated showers in the morning, then mostly sunny in the afternoon. Highs 82 to 89. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 69 to 74. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Friday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 82 to 89. East winds around 10 mph. Chance of rain 30 percent.

Kaua’i Mountains

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 88 in the valleys to 64 to 70 above 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 66 to 72 in the valleys to around 58 above 4000 feet. Light winds. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs 76 to 89 in the valleys to 64 to 69 above 4000 feet. Southeast winds up to 10 mph. Chance of rain 50 percent.

North Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs 79 to 90. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Isolated showers. Lows 66 to 74. Southeast winds up to 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 79 to 90. Southeast winds up to 15 mph. Chance of rain 20 percent.

East Kaua’i

Today: Partly sunny with isolated showers. Highs 76 to 87. Northeast winds up to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 66 to 76. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 40 percent.

Friday: Partly sunny in the morning then becoming mostly sunny. Isolated showers. Highs 77 to 87. Southeast winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Gentle to moderate trade winds will trend weaker through Friday, then gradually strengthen through the weekend to become moderate to breezy by early next week. Limited low clouds and showers will favor windward and mauka areas with the exceptions being on Friday when winds become light enough to allow for sea breeze development and Friday night into Saturday as a plume of slightly enhanced moisture moves through the state.

Discussion

A low pressure system is situated about 1100 miles northeast of the state as of this morning. This low is weakening the ridge that is extending across the Eastern and Central Pacific, which in turn is reducing the pressure gradient across the state. Gentle to moderate trade winds will become light to gentle by Friday as the low pressure system broadens to our north. With a fairly dry and stable airmass over the state, limited clouds and showers will remain concentrated over windward and mauka areas into early next week. Some showers may spill over to leeward areas during the overnight night hours. Chances of clouds and showers may increase slightly over leeward interior areas Friday afternoon as light winds support sea breeze development. For Kona slopes of the Big Island, clouds will increase in coverage during the daytime hours as sea breezes develop and then clear/push offshore overnight as land breezes kick in.
Global models show a subtle plume of enhanced moisture moving across the state Friday night through Saturday, a slight uptick in low clouds and showers to windward and mauka areas is expected through that period. Dewpoint temperatures will also creep up in the low 70's making air temperatures feel slightly warmer over the weekend and linger into next week.
Moderate to locally breezy trade winds will then gradually return over the weekend into early next week as the low lifts further northeastward, allowing the ridge to strengthen northeast of the state.

Aviation

A mostly dry and stable airmass over the islands will limit cloud and shower development, with moderate trade winds continuing through the rest of week. VFR conditions expected to prevail.
No AIRMETs are in effect, and none are expected today.

Marine

Trade winds will gradually ease through Friday as a broad area of low pressure deepens far northeast of the state. Wind speeds will restrengthen to moderate to locally strong levels over the weekend as the ridge to the north builds back over the islands.
A moderate south swell will continue to build through the day, peaking Friday night, then slowly decline over the weekend. Surf heights at the peak of the swell should remain just below High Surf Advisory criteria.
Surf along east facing shores will slowly decline by the end of the week as trade winds decline. Surf along north facing shores will remain tiny through the end of the week. 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