Photo Credit: Jason Weingardt

West Kaua’i

Today: Mostly sunny. Isolated showers in the afternoon. Highs 84 to 90 near the shore to around 76 above 3000 feet. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Isolated showers early in the evening. Lows around 68 near the shore to around 58 above 3000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the late morning and afternoon. Highs 85 to 91 near the shore to around 77 above 3000 feet. Light winds. Chance of rain 20 percent.

South Kaua’i

Today: Sunny. Isolated showers in the afternoon. Highs 84 to 90. Light winds. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 68. Light winds.

Thursday: Mostly sunny. Isolated showers in the late morning and afternoon. Highs 85 to 91. Light winds. Chance of rain 20 percent.

Kaua’i Mountains

Today: Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 75 to 82 in the valleys to around 67 above 4000 feet. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers early in the evening. Lows 61 to 66 in the valleys to around 56 above 4000 feet. Light winds. Chance of rain 20 percent.

Thursday: Sunny early in the morning, then partly sunny with isolated showers in the late morning and afternoon. Highs 76 to 84 in the valleys to around 68 above 4000 feet. Light winds. Chance of rain 20 percent.

North Kaua’i

Today: Mostly sunny. Isolated showers in the afternoon. Highs 78 to 87. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers early in the evening. Lows 62 to 70. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the late morning and afternoon. Highs 79 to 87. Light winds. Chance of rain 20 percent.

East Kaua’i

Today: Mostly sunny. Isolated showers in the afternoon. Highs 76 to 88. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers early in the evening. Lows 61 to 73. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the late morning and afternoon. Highs 77 to 88. Light winds. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Background flow will remain light through Thursday. These light winds will allow afternoon sea breezes and nighttime land breezes to develop, with mostly clear nights and mornings followed by clouds and spotty showers each afternoon over leeward and interior sections. Locally breezy trade winds are expected to return this weekend as a strong high builds far northwest of the islands. A front approaching the western islands early next week may cause an increase in shower coverage over portions of the island chain.

Discussion

Weak ridging near the islands will bring light and variable winds across the western half of the state with light east to southeasterly winds over the eastern half. The light wind flow will result in daytime sea breezes and nighttime land breezes over the next couple of days, resulting in sunny skies in the morning, cloud build ups with isolated showers during the afternoons, then clearing at night.
Trade winds will slowly strengthen Friday as the ridge lifts further north. By the weekend, strong high pressure will build far northwest of the state and increase trade winds across the islands to locally breezy levels. As this high builds, a front will be pushed southward towards Kauai by late Sunday into Monday that may bring increased windward-focused rainfall to portions of the island chain early next week. However, some differences persist between the GFS and ECMWF solutions as to whether the front will move onto Kauai or stall before reaching the state. Trade winds will remain elevated into early next week.

Aviation

Light and variable winds will allow overnight land breezes and daytime sea breezes to form as a ridge remains in the area. Expect increased cloud cover and possible light showers across mountain/interior locations as sea breezes form. Clouds and showers will then decrease in coverage tonight as the land breezes form.
AIRMET Sierra for MTN OBSC across E thru SE slopes of Oahu is in effect. If conditions continue to improve, this will be cancelled later this morning.

Marine

A surface ridge will remain anchored over the western end of the state through Thursday, keeping light and variable winds over the western islands, while light to locally moderate east-southeast trades hold over the eastern end of the state. Ridging will build back north of the islands Thursday night and Friday, allowing the trade winds to return. A strengthening surface high to the distant northwest will allow trades to strengthen to moderate and strong levels Friday night through Monday. Small Craft Advisories will likely be needed as early as Friday night for some waters, then possibly expand to most marine zones Saturday night through early next week.
Surf along north facing shores will remain below the seasonal average this week. A new reinforcing north-northwest swell will arrive today, giving north shore surf a modest boost. A steady train of overlapping moderate-sized north-northwest swells will then continue to move through the islands through early next week, with only minor changes in surf heights from day to day.
The current south swell will keep south shore surf above the seasonal average today, with a gradual decline on Thursday. A new long-period, south-southwest swell will arrive late Thursday and linger through early next week, keeping some small surf in place along south facing shores. East shore surf will remain small through at least Saturday, due to the lack of upstream trade winds. East shore surf will gradually rise Sunday into early next week as the trades return and ramp up.
Higher than predicted water levels are expected to trend down across the Hawaiian Islands over the next few days. However, water levels look to remain elevated enough for the western end of the island chain to result in minor coastal flooding again this morning for Niihau, Kauai, and Oahu during the high astronomical tide. The Coastal Flood Statement remains in effect for these areas through 8 am this morning.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov