West Side

Today: Sunny. Highs around 79. Light winds becoming southwest around 10 mph in the afternoon.

Tonight: Partly cloudy. Lows 67 to 73. Light winds.

Thursday: Mostly sunny. Highs 76 to 81. Light winds.

South Side

Today: Sunny. Highs around 84. North winds up to 10 mph shifting to the southwest around 10 mph in the afternoon.

Tonight: Mostly clear. Lows 65 to 75. Light winds.

Thursday: Mostly sunny. Highs around 83. North winds up to 10 mph.

North Shore

Today: Mostly sunny with isolated showers. Highs around 81 near the shore to around 66 near 5000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 69 near the shore to around 51 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny with isolated showers. Highs around 80 near the shore to around 65 near 5000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Central Maui

Today: Sunny. Highs around 83. Light winds.

Tonight: Mostly clear. Lows 65 to 70. Light winds.

Thursday: Mostly sunny. Highs around 82. North winds up to 10 mph.

Upcountry

Today: Mostly sunny. Isolated showers in the afternoon. Highs around 62 at the visitor center to around 69 at the summit. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers early in the evening. Lows around 46 at the visitor center to around 48 at the summit. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs around 61 at the visitor center to around 69 at the summit. Light winds becoming northwest up to 10 mph in the afternoon. Chance of rain 20 percent.

East Maui

Today: Mostly sunny with isolated showers. Highs around 81 near the shore to around 66 near 5000 feet. East winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 69 near the shore to around 51 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny with isolated showers. Highs around 80 near the shore to around 65 near 5000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Lanai City

Today: Mostly sunny. Isolated showers in the afternoon. Highs 71 to 77. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers early in the evening. Lows around 65. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs 70 to 78. Light winds. Chance of rain 20 percent.

Kaunakakai

Today: Mostly sunny. Isolated showers in the afternoon. Highs 68 to 84. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers early in the evening. Lows 57 to 71. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs 68 to 84. Light winds. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A surface ridge will maintain light winds with land and sea breezes for the next couple of days. Isolated showers will affect windward sections of the eastern islands overnight into the early morning hours, and the island interiors each afternoon and early evening. A weak front could increase showers late Thursday night through Saturday as it moves southeastward into the islands. Another stronger front could increase shower coverage as well as bring breezy southwesterly winds late Sunday into early next week.

Discussion

Currently at the surface, a 1028 mb high is centered to the distant northeast, with a ridge axis extending southwestward from the high to a location over the western end of the state. This is resulting in light winds with land breezes present across the island chain. Infrared satellite imagery shows mostly clear skies across the state, with radar imagery showing a few showers over the coastal waters and brushing east and southeast facing slopes of Maui and the Big Island. Main short term focus revolves around minimal rain chances during the next couple of days.
The ridge of high pressure over the western end of the state will shift slowly southeastward during the next couple of days as a cold front approaches from the northwest. This will keep a light wind regime in place across the state. As a result, a few showers will affect windward locations over the eastern end of the state overnight and during the morning hours, with a few showers then possible over the island interiors each afternoon before fizzing out in the early evening hours.
Models are in good agreement showing a cold front moving into Kauai late Thursday night, then decaying as it shifts southeastward down the island chain Friday and Saturday. The front will bring an increase in clouds and showers as it moves through, but with the best forcing remaining well north of the state, no significant rainfall is expected. The old front or its remnant moisture should lift back north of the islands on Sunday, as yet another front approaches from the northwest. This front appears stronger, with moderate to breezy southwesterly winds developing in advance late Sunday into Monday. The front appears to move through the state later Monday through Tuesday, accompanied by a line of heavier showers with potentially gusty winds.

Aviation

Light southeasterly background flow will give way to a land and seabreeze pattern through the forecast period. This will provide some interior clouds during the afternoon, that will dissipate overnight. VFR conditions are expected to prevail.
Currently, no AIRMETS are in effect.

Marine

Light winds will prevail through Thursday as a surface ridge remains over the islands. The background flow will remain out of the southeast for Maui and the Big Island waters and out of the south to southwest over the Kauai and Oahu waters. While most coastal areas will experience typical overnight land breezes and afternoon sea breezes, terrain-induced accelerations will lead to brief periods of locally enhanced winds where the flow parallels to the coast, particularly through the afternoon hours. Moderate to fresh northerly winds will gradually fill in on Friday as a cold front moves into the area.
Surf along exposed north- and west-facing shores will remain around the advisory levels through the early morning hours today, then gradually lower by this afternoon. Offshore buoy observations to the northwest already show a downward trend, which should be reflected at the nearshore buoys later today as the swell eases.
A more significant northwest swell is expected through the second half of the week and weekend from a broad and complex low that has evolved over the far northwest Pacific in the past few days. Latest analysis and satellite imagery show this system positioned over the far northwest Pacific near the western Aleutians, with a captured fetch focused at the islands within the 290 to 315 degree directional bands. This swell will begin building down the island chain Thursday and will be a long-duration event, with a peak centered around the Friday through Saturday time frame. Heights will exceed advisory levels by Thursday, then warning levels Friday through Saturday.
Impacts associated with the warning-level surf Friday through Saturday will likely lead to some water reaching areas that typically remain dry along exposed coasts, including vulnerable low-lying roadways and infrastructure. This likelihood will especially increase if the peak surf coincides with the overnight high tide cycle Friday night.
Surf along east-facing shores will remain small due to the lack of trades locally and upstream of the state.
Surf along south-facing shores will remain up today before easing Thursday as a small, long-period south-southwest swell moves through.

HFO Watches/Warnings/Advisories

High Surf Advisory until noon HST today for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Maui Windward West, Kauai North, Molokai Windward, Molokai North, Molokai West, Maui Central Valley North, Windward Haleakala.

Data Courtesy of NOAA.gov