Photo Credit: Brendan Stephen

West Kaua’i

Today: Sunny. Highs 86 to 92 near the shore to around 78 above 3000 feet. Northeast winds up to 15 mph shifting to the northwest in the afternoon.

Tonight: Mostly clear. Isolated showers after midnight. Lows around 72 near the shore to around 62 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Friday: Sunny and breezy. Highs 86 to 91 near the shore to around 77 above 3000 feet. East winds up to 20 mph.

South Kaua’i

Today: Breezy. Mostly sunny with isolated showers. Highs 85 to 91. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Isolated showers. Lows 70 to 75. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Friday: Mostly sunny. Breezy. Isolated light showers in the morning. Highs 85 to 90. Northeast winds 15 to 20 mph. Chance of rain 20 percent.

Kaua’i Mountains

Today: Partly sunny with scattered showers. Highs 76 to 85 in the valleys to around 69 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 71 in the valleys to around 59 above 4000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Friday: Partly sunny. 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 up to 15 mph. Chance of rain 50 percent.

North Kaua’i

Today: Mostly sunny. Scattered showers early in the morning, then isolated showers in the late morning and afternoon. Highs 77 to 89. East winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 30 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 66 to 74. East winds up to 15 mph. Chance of rain 40 percent.

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

East Kaua’i

Today: Partly sunny early in the morning then becoming mostly sunny. Isolated showers. Highs 75 to 88. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 77. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Friday: Mostly sunny with isolated light showers. Highs 75 to 87. 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 mainly windward showers will continue through the week.

Discussion

Typical summertime trade wind weather will dominate through the week. Strong high pressure will remain anchored far north of the islands, driving moderate to breezy trade winds, and a mid-level ridge parked overhead will maintain stable conditions with an inversion hovering between 5,000 to 8,000 ft. Shallow pockets of moisture riding in on the trades will periodically enhance windward rainfall, mainly at night and early in the morning, with one such area focused from Oahu to Maui this morning. No strong rainfall signatures are noted in the model guidance, though Friday and Saturday look to have some decrease in shower activity. Leeward areas will be rather dry, with the exception of afternoon clouds and scattered showers over leeward Big Island slopes each day.

Aviation

Quick-moving trade winds will persist through the evening hours, then weaken a bit on Friday. Clouds and scattered showers will mainly affect windward locations, with isolated showers occasionally spilling over to leeward locations.
AIRMET Sierra is in effect for windward exposures of Kauai, Oahu, Molokai, and Maui. Conditions are expected to improve toward noon as daytime heating encourages low clouds to lift and dissipate.
AIRMET Tango remains in effect for occasional moderate low-level turbulence to the lee of higher terrain. Conditions are expected to persist through this evening and possibly beyond.

Marine

A surface high pressure system located far north of the state will maintain locally strong trade winds across the area into early next week. A Small Craft Advisory (SCA) remains in effect through Saturday afternoon for the typically windier waters adjacent to the islands of Maui County and the Big Island. Based on the latest forecast, this SCA will likely need to be extended beyond Saturday for these same areas.
No significant swells are expected through this weekend. A mix of small, medium-period south and southwest swell energy is expected to produce small, background surf along south facing shores into this weekend. The wave model guidance indicates a small, long- period southwest swell arriving Sunday may produce a bump in surf heights along south facing shores early next week. The trade winds will likely maintain modest, choppy surf along east facing shores through this weekend. Expect nearly flat conditions to persist along north facing shores.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov