West Side

Today: Breezy. Mostly sunny with isolated showers. Highs 73 to 84. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 65 to 74. Northeast winds 10 to 15 mph. Chance of rain 40 percent.

Sunday: Breezy. Mostly sunny with isolated showers. Highs 74 to 84. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

South Side

Today: Mostly sunny. Breezy. Highs 70 to 85. Northeast winds 10 to 20 mph.

Tonight: Partly cloudy. Lows 61 to 72. North winds up to 15 mph increasing to 10 to 15 mph after midnight.

Sunday: Mostly sunny. Breezy. Highs 70 to 85. Northeast winds 10 to 20 mph.

North Shore

Today: Breezy. Partly sunny with scattered showers. Highs 78 to 83 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 69 to 74 near the shore to around 55 near 5000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 70 percent.

Sunday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to around 66 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Central Maui

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Upcountry

Today: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs 50 to 68. East winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 46 at the visitor center to around 42 at the summit. East winds up to 10 mph. Chance of rain 50 percent.

Sunday: Partly sunny with scattered showers. Highs 52 to 69. East winds up to 10 mph. Chance of rain 50 percent.

East Maui

Today: Breezy. Partly sunny with scattered showers. Highs 78 to 83 near the shore to around 65 near 5000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 69 to 74 near the shore to around 55 near 5000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 70 percent.

Sunday: Partly sunny. Breezy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to around 66 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Lanai City

Today: Sunny and breezy. Highs 68 to 78. Northeast winds 10 to 20 mph.

Tonight: Mostly clear. Lows 60 to 67. Northeast winds 10 to 15 mph.

Sunday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs 69 to 79. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Kaunakakai

Today: Breezy. Mostly sunny with isolated showers. Highs 67 to 85. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers after midnight. Lows 57 to 72. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Sunday: Breezy. Mostly sunny with isolated showers. Highs 67 to 84. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

The high pressure ridge north of the islands will keep moderate trade winds blowing across the Hawaii region through Monday. Wind speeds will weaken from Tuesday through Thursday as a weak cold front passes north of the island chain. Trade winds slowly return by the end of next week as the ridge builds back into the region.

Discussion

The satellite water vapor imagery this morning shows a weak upper low roughly 400 miles northeast of the Big Island. Clouds just upstream or east of the Big Island are fairly unstable looking, keeping periods of rainfall in the forecast for the Hamakua Coast and east Maui today. Subsidence temperature inversion heights in this mornings upper air sounding at Hilo and Lihue were measured at 7,500 feet and 6,300 feet respectively. This means cloud heights are taller across the eastern islands with enhanced shower potential, as compared lower cloud tops and more normal brief passing showers across to the western half of the state.
Moderate trade winds continue with brief passing showers favoring the windward mountain areas through Monday. Lighter winds from Tuesday through Thursday will cause afternoon sea breezes with onshore winds, triggered by island surface heating, to expand across all islands. Expect interior clouds and a few showers each day in this pattern. Trade winds slowly rebuild across the state by the end of next week.

Aviation

Moderate to breezy easterly trades will persist today, with clouds and brief showers favoring windward and mauka locations. Expect periods with MVFR CIGS/VSBYS in showers moving through, particularly through the early morning hours.
No AIRMETS are in effect.

Marine

A ridge of high pressure to the north of the islands will weaken through the weekend as a front passes north of the islands. Winds in turn will weaken, and further ease Tuesday into the middle of the week as another front passes north of the islands.
A small west-northwest swell this morning is coming in a little lower than expected, the swell will hold through the morning and then gradually ease through the weekend. Another, slightly smaller northwest swell is expected early next week, maintaining elevated surf along north and west- facing shores. Looking ahead, guidance indicates yet another long- period northwest (320 deg) swell may arrive late next week, generated by a developing storm near Japan that is forecast to lift northeast near the Kuril Islands over the weekend.
Surf along south-facing shores will trend up this weekend as a long- period south-southwest pulse arrives. Expect a peak later in the weekend and into Monday before lowering.
As trade winds weaken this weekend, expect surf along east- facing shores to trend downward.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov