Photo Credit: Sebastien Gabriel

West Kaua’i

Today: Mostly sunny with isolated showers. Highs 86 to 92 near the shore to around 77 above 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 72 near the shore to around 62 above 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Thursday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 86 to 91 near the shore to around 77 above 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

South Kaua’i

Today: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 84 to 90. East winds 15 to 20 mph. Chance of rain 50 percent.

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows 71 to 76. East winds 15 to 20 mph. Chance of rain 50 percent.

Thursday: Partly sunny in the morning then becoming mostly sunny. Breezy. Scattered showers. Highs 85 to 91. East winds 15 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Today: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 75 to 85 in the valleys to around 68 above 4000 feet. East winds 15 to 20 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening, then showers likely after midnight. Lows 66 to 71 in the valleys to around 60 above 4000 feet. East winds 15 to 20 mph. Chance of rain 70 percent.

Thursday: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 75 to 84 in the valleys to around 68 above 4000 feet. East winds 15 to 20 mph. Chance of rain 70 percent.

North Kaua’i

Today: Breezy. Partly sunny with scattered showers. Highs 78 to 89. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 66 to 74. East winds 10 to 20 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 78 to 89. East winds 10 to 20 mph. Chance of rain 50 percent.

East Kaua’i

Today: Breezy. Partly sunny with scattered showers. Highs 75 to 88. East winds 15 to 20 mph. Chance of rain 50 percent.

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

Thursday: Breezy. Partly sunny with scattered showers. Highs 76 to 88. East winds 15 to 20 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

Expect our breezy trade wind weather to continue through the weekend, with clouds and showers favoring windward and mauka areas. Total rainfall will be light as a persistent subsidence inversion caps cloud and shower development.

Discussion

High pressure far north of the main Hawaiian Islands continues to drive moderate to breezy trade winds across local waters this morning. Overnight soundings show a stable airmass and PW values ranging from 1.52 to 1.38 inches, close to normal for this time of year. A strong subsidence inversion near 5200 feet remains a feature, limiting cloud and shower development. Satellite loop shows a persistent broad field of stable broken to overcast low clouds extending from Hawaiian windward waters almost all the way to the mainland. The western edge of this cloud field covers most windward shores and slopes at this hour. However, except for light showers passing through the Kauai and Kaiwi Channels, radar corroborates the effects of the capping inversion by showing little shower activity beneath this cloud cover.
Forecast philosophy, like the synoptic setup, remains unchanged from last evening. Models show high pressure will remain parked far north of the islands through the week, while ridging aloft caps cloud and shower development. This pattern will keep the state embedded within trade wind flow. Moderate to breezy east northeast trade winds will continue into the foreseeable future. Limited showers riding in on the trades will focus over windward shores and slopes. The leeward side of the Big Island will see a diurnal pattern of mostly clear skies in the morning and then increasing clouds and scattered showers each afternoon before clearing again overnight.

Aviation

Moderate to locally breezy trade winds will persist through today then gradually weaken on Thursday and Friday. Clouds and scattered showers will mainly affect windward locations with isolated showers occasionally spilling over to leeward locations. There may be brief periods of MVFR conds associated with this activity.
AIRMET Tango remains in effect for occasional moderate low level turbulence to the lee of higher terrain. Conditions are likely to persist through at least early evening.
AIRMET Sierra for mountain obscuration is now in effect for north and east facing exposures of all all major islands. Conditions are expected to persist through at least mid-morning. Low clouds should lift and clear most areas by afternoon.

Marine

Surface high pressure generally centered north of the islands will remain nearly stationary through the remainder of the week. The high is producing a tight enough pressure gradient down across the Central Pacific to maintain fresh to locally strong trade winds across the island's near and offshore waters the next several days. The Small Craft Advisory (SCA) for winds remains in effect for the typical windier waters surrounding Maui County and Big Island through Friday afternoon.
No significant incoming swell will allow for the continuance of small surf along all shores this week. Small, medium to slightly longer period southern swells will support small surf along many south-facing shores. A storm passing around New Zealand through mid week may push a small, long period southwest swell far enough north to slightly lift south-facing shore surf by another foot early next week. A nice long fetch of upstream fresh trade flow will keep small and choppy surf in place along eastern exposures for the foreseeable future.

HFO Watches/Warnings/Advisories

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

Data Courtesy of NOAA.gov