Photo Credit: Jason Weingardt

West Kaua’i

Today: Sunny. Highs 86 to 91 near the shore to around 77 above 3000 feet. East winds 10 to 15 mph.

Tonight: Mostly clear. Lows around 72 near the shore to around 62 above 3000 feet. East winds 10 to 15 mph.

Saturday: Sunny. Highs 87 to 92 near the shore to around 78 above 3000 feet. East winds 10 to 15 mph.

South Kaua’i

Today: Mostly sunny. Breezy. Isolated light showers in the morning. Highs 85 to 90. East winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Breezy. Partly cloudy with isolated light showers. Lows around 73. East winds 15 to 20 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Isolated light showers in the morning. Highs 85 to 91. East winds 10 to 15 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny. Breezy. Scattered light showers in the morning, then isolated light showers in the afternoon. Highs 74 to 84 in the valleys to around 68 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered light showers. Lows 66 to 71 in the valleys to around 60 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Saturday: Partly sunny. Breezy. Scattered light showers in the morning, then isolated light showers in the afternoon. Highs 75 to 85 in the valleys to around 68 above 4000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny. Scattered light showers in the morning, then isolated light showers in the afternoon. Highs 78 to 88. East winds 10 to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with isolated light showers. Lows 66 to 74. East winds 10 to 15 mph. Chance of rain 20 percent.

Saturday: Mostly sunny with isolated light showers. Highs 78 to 90. East winds 10 to 15 mph. Chance of rain 20 percent.

East Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Isolated light showers. Highs 75 to 87. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated light showers. Lows 66 to 78. East winds 10 to 15 mph. Chance of rain 20 percent.

Saturday: Partly sunny in the morning then becoming mostly sunny. Isolated light showers. Highs 76 to 88. East winds 10 to 15 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate to breezy trade winds and a typical summertime pattern of limited windward showers and rather dry leeward conditions will continue through the week.

Discussion

A stable and breezy trade wind flow persists. Strong high pressure anchored far north of the islands is driving the breezy trade winds, and a mid-level ridge parked overhead is producing stable conditions with an inversion hovering between 4,000 to 7,000 ft. The GFS and ECMWF models suggest a decrease in trade wind showers through Saturday, supported by satellite data showing precipitable water dropping just east of the state in a cloud field dominated by stratocumulus. Expect limited rainfall to be confined to windward slopes, and with the exception of afternoon clouds and showers over the Kona slopes of the Big Island, leeward areas will be dry.
Trade winds will hold at moderate to breezy strength Sunday through the middle of next week, and ridging aloft will persist. As a result, only minor changes to the rainfall pattern are due as random pockets of shallow moisture move through.

Aviation

A high pressure ridge far north of the Hawaiian Islands will keep moderate to locally breezy trade winds in the forecast into the weekend. Brief periods of showers are possibly especially during the overnight to early morning hours. VFR conditions will prevail outside of showers.
AIRMET Tango remains in effect for moderate low level turbulence over and downwind of island mountains. Conditions are expected to continue through the weekend.

Marine

A surface high pressure system located far north of the state will maintain locally strong trade winds across the area through early next week. A Small Craft Advisory (SCA) remains in effect through this weekend for the typically windier waters adjacent to the islands of Maui County and the Big Island. In addition, recent scatterometer data showed winds of near 25 knots in the Kaiwi Channel, so that zone has been added to the SCA through Saturday. The latest forecast indicates the SCA will need to be extended for the windier waters from Monday through Tuesday.
No significant swells are expected through this weekend. A mix of small, medium-period south and southwest swell energy will produce small surf along south facing shores this morning. Surf will eventually return to tiny background heights heading into the weekend. Forerunners from a new small, long-period southwest swell are expected to arrive late Sunday, which will likely provide an increase in surf heights along south facing shores early next week. The locally strong trade winds are expected to maintain modest, choppy surf along east facing shores through early next week. Expect nearly flat conditions to persist along north facing shores.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov