West Side

Tonight: Partly cloudy with isolated showers. Haze. Lows 67 to 73. East winds around 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny with isolated showers. Haze. Highs around 81. East winds around 10 mph. Chance of rain 20 percent.

Friday Night: Mostly clear. Haze. Lows 66 to 72. East winds around 10 mph.

South Side

Tonight: Partly cloudy. Haze. Lows 65 to 75. East winds 10 to 15 mph.

Friday: Mostly sunny. Haze through the day. Highs around 87. East winds 10 to 15 mph.

Friday Night: Partly cloudy. Haze. Lows 65 to 74. East winds 10 to 15 mph.

North Shore

Tonight: Breezy. Partly cloudy with scattered showers. Haze. Lows around 70 near the shore to around 51 near 5000 feet. Southeast winds 10 to 20 mph. Chance of rain 40 percent.

Friday: Breezy. Mostly sunny with scattered showers. Highs 78 to 83 near the shore to around 67 near 5000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Friday Night: Breezy. Partly cloudy with scattered showers. Lows around 69 near the shore to around 50 near 5000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Central Maui

Tonight: Partly cloudy. Haze. Lows around 67. East winds 10 to 15 mph.

Friday: Mostly sunny. Haze in the morning. Highs 82 to 88. East winds 10 to 15 mph.

Friday Night: Mostly clear. Lows around 67. East winds 10 to 15 mph.

Upcountry

Tonight: Partly cloudy. Haze. Lows 42 to 54. East winds 10 to 15 mph.

Friday: Mostly sunny. Haze. Highs around 62 at the visitor center to around 56 at the summit. East winds 10 to 15 mph.

Friday Night: Partly cloudy. Haze. Lows around 44 at the visitor center to around 42 at the summit. East winds 10 to 15 mph.

East Maui

Tonight: Breezy. Partly cloudy with scattered showers. Haze. Lows around 70 near the shore to around 51 near 5000 feet. Southeast winds 10 to 20 mph. Chance of rain 40 percent.

Friday: Breezy. Mostly sunny with scattered showers. Highs 78 to 83 near the shore to around 67 near 5000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Friday Night: Breezy. Partly cloudy with scattered showers. Lows around 69 near the shore to around 50 near 5000 feet. East winds 10 to 20 mph. Chance of rain 20 percent.

Lanai City

Tonight: Partly cloudy. Isolated showers in the evening. Haze through the night. Lows around 64. Southeast winds around 10 mph. Chance of rain 20 percent.

Friday: Mostly sunny. Haze. Highs 72 to 80. South winds around 10 mph shifting to the west in the afternoon.

Friday Night: Mostly clear. Haze. Lows 61 to 66. West winds 10 to 15 mph shifting to the north after midnight.

Kaunakakai

Tonight: Partly cloudy. Haze. Lows 56 to 72. East winds 10 to 15 mph.

Friday: Mostly sunny. Haze. Highs 69 to 86. East winds around 10 mph.

Friday Night: Mostly clear. Haze. Lows 55 to 71. East winds around 10 mph.

Detailed Forecast

Synopsis

Moderate east-southeast winds will prevail during the next couple days, with showers favoring leeward areas in the afternoon and east and southeast facing slopes and coasts at night. Winds will ease Sunday through Tuesday, with land and sea breezes becoming dominant. Showers will favor interior and leeward areas during the afternoon and evening, and areas near the immediate coast at night. A disturbance aloft could bring some unsettled weather and more intense showers of the islands early next week. A return to more typical trade wind weather featuring mainly windward and mauka showers may return during the middle to latter part of next week.

Discussion

Currently at the surface, a broad 1010 mb low is positioned around 725 miles northwest of Kauai, while a 1030 mb high is centered around 1300 miles north-northeast of Honolulu. Between these two features lies a trough of low pressure which is located around 100 miles west of Kauai. Infrared satellite imagery shows partly to mostly cloudy conditions, with clouds coverage the highest over the western end of the state. Radar imagery shows a few showers moving into southeast facing slopes and coasts, along with some spotty leeward shower activity. Main short term focus revolves around trends in the winds and rain chances during the next few days.
The broad low northwest of the islands and the high to the distant north-northeast will remain nearly stationary tonight and Friday, keeping moderate east-southeast winds in place across the island chain. The broad low will shift eastward this weekend, then dampen into a trough over the islands early next week. This will ease the east-southeast winds and allow land and sea breezes to become dominant across the state. Broad troughing over the islands will gradually dampen out during the middle and latter part of next week as high pressure builds north of the islands. This should allow a gradual return and strengthening of the trade winds across the state.
As for the remaining weather details, lingering daytime heating showers should diminish in the next couple hours, with isolated to scattered showers then moving into east and southeast facing slopes and coasts overnight. The overall weather pattern will remain mostly unchanged during the next couple days, with showers favoring leeward areas in the afternoon and evening hours, and east and southeast facing slopes and coasts overnight and during the morning hours. Lingering instability could result in thunderstorm or two over the Big Island Friday afternoon. A land/sea breeze pattern should then take hold Sunday through Tuesday, with showers favoring interior and leeward areas during the afternoon and evening hours, with most showers over the coastal waters or near the immediate coast overnight. A disturbance aloft diving southward over the state could bring some more intense shower activity early next week. A return to more typical trade wind weather featuring mainly windward and mauka showers may return during the middle to latter part of next week.

Aviation

Stable, light to locally moderate southeasterlies and VFR conditions prevail areawide this evening. Clouds and showers may produce MVFR conditions mostly in the vicinity of Kauai and Oahu through tonight. Land and sea breezes are expected across most of the state with sheltered and leeward areas capable of producing brief MVFR during the afternoon hours.
No AIRMETs are currently in effect.

Marine

Locally fresh southeast winds persist through Saturday as a trough remains nearly stationary north and west of the islands. Light flow Sunday through Tuesday will transition to a typical trade wind pattern around the middle of next week.
Existing small northwest swell will continue to fade through the day Friday providing little in the way of surf for north and west facing shores. Slightly larger long-period northwest swell is forecast this weekend, though surf should still remain well below advisory thresholds for north and west facing shores.
Ongoing small, medium to long period, south swell will slowly decline through late Friday with mainly small background south swell energy continuing into the weekend. A lack of upstream trades will favor below average surf along east facing shores.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov