Photo Credit: Jason Weingardt

West Kaua’i

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 84 near the shore to around 72 above 3000 feet. Northeast winds up to 15 mph shifting to the southeast in the afternoon. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 68 to 73 near the shore to around 59 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Thursday: Mostly sunny with isolated showers. Highs around 85 near the shore to around 73 above 3000 feet. Northeast winds up to 15 mph shifting to the southwest in the afternoon. Chance of rain 20 percent.

South Kaua’i

Today: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 81. Northeast winds 10 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 72. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 82. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Kaua’i Mountains

Today: Mostly cloudy. Frequent showers in the morning, then scattered showers in the afternoon. Highs 71 to 78 in the valleys to around 62 above 4000 feet. East winds up to 10 mph. Chance of rain 80 percent.

Tonight: Mostly cloudy. Numerous showers in the evening, then frequent showers after midnight. Lows 59 to 64 in the valleys to around 54 above 4000 feet. East winds up to 15 mph. Chance of rain 80 percent.

Thursday: Mostly cloudy. Frequent showers in the morning, then scattered showers in the afternoon. Highs 72 to 79 in the valleys to around 63 above 4000 feet. East winds up to 15 mph. Chance of rain 80 percent.

North Kaua’i

Today: Partly sunny with scattered showers. Highs 74 to 83. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 62 to 72. Southeast winds up to 15 mph. Chance of rain 70 percent.

Thursday: Partly sunny with scattered showers. Highs 75 to 84. East winds up to 15 mph. Chance of rain 50 percent.

East Kaua’i

Today: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 74 to 82. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 60 to 73. Northeast winds up to 15 mph. Chance of rain 70 percent.

Thursday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs 75 to 83. Northeast winds 10 to 15 mph. Chance of rain 70 percent.

Detailed Forecast

Synopsis

Moderate to breezy easterly trade winds will continue through early next week, with clouds and showers favoring windward and mauka locations as pockets of moisture move through. Expect some showers to carry over into leeward areas periodically due to a weak upper disturbance in the area, especially overnight through the morning periods.

Discussion

Guidance remains in good agreement through the weekend and depicts the subtropical ridge remaining anchored north of the state. Although a mostly stable summertime regime is expected, a weak upper low drifting overhead will introduce some variability to the pattern, especially as pockets of moisture move through. A combination of the added instability associated with this upper feature, bands of moisture moving through, and an elevated inversion will support periods of showery conditions. Breezy easterly trades will focus most of the shower coverage over windward and mauka locations, with some becoming briefly heavy and spilling over into our leeward areas that have become dry over the past few weeks.

Aviation

Moderate to locally breezy ENE trades will remain in place today and tonight, strongest during the late morning and afternoon hours when some gustiness can be expected. Clouds and showers will be most prevalent in windward and mauka areas this morning, with a few showers reaching leeward locales at times. Some MVFR cigs/vsbys will accompany the showers in windward areas, with VFR conditions expected in leeward locales.
AIRMET Sierra remains in effect for mountain obscuration over windward sections of Kauai, Molokai, Maui and the Big Island. Conditions may expand to windward Oahu later this morning. Improving conditions are expected in all areas by noon.
AIRMET Tango remains in effect for moderate turbulence over and downwind of the terrain of all islands. This AIRMET will likely remain in place through the day.

Marine

A surface high pressure system located far northeast of the state will maintain moderate to locally strong easterly trade winds through this weekend. A Small Craft Advisory (SCA) has been extended through Friday night for the typically windier waters adjacent to the islands of Maui County and the Big Island. The latest forecast keeps SCA conditions in these same waters this weekend.
A mix of small, long-period south and south-southwest (170-220 degrees) swells will maintain small background surf along south facing shores through this weekend. Choppy, moderate surf will persist along east facing shores due to the trade winds locally, and upstream of the islands. Expect some minor fluctuations in surf heights along east facing shores in response to small changes in trade wind speeds into early next week. The current small, short-period northwest (320 degrees) swell will linger into Friday. An out-of-season, medium-period west-northwest (300-310 degrees) swell generated by former Northwest Pacific Typhoon Guchol is forecast to arrive this weekend. This swell is expected to provide a boost to surf along exposed north and west facing shores from Sunday into early next week.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov