West Side

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy after midnight. Lows 71 to 79. Northeast winds up to 15 mph. Chance of rain 20 percent.

Thursday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 79 to 87. Northeast winds up to 15 mph. Chance of rain 50 percent.

Thursday Night: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 71 to 80. Light winds. Chance of rain 50 percent.

South Side

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Lows 72 to 79. North winds 10 to 15 mph.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs around 87. North winds 10 to 15 mph. Chance of rain 20 percent.

Thursday Night: Partly cloudy in the evening, then mostly cloudy with scattered showers after midnight. Lows 73 to 79. North winds 10 to 15 mph shifting to the northeast after midnight. Chance of rain 40 percent.

North Shore

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows around 75 near the shore to around 59 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 50 percent.

Thursday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 82 near the shore to around 71 near 5000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows around 75 near the shore to around 60 near 5000 feet. East winds up to 10 mph. Chance of rain 60 percent.

Central Maui

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy after midnight. Lows 71 to 77. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Thursday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 81 to 87. Northeast winds 10 to 15 mph shifting to the north in the afternoon. Chance of rain 40 percent.

Thursday Night: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 73 to 78. Light winds. Chance of rain 50 percent.

Upcountry

Tonight: Mostly cloudy with isolated showers in the evening, then partly cloudy after midnight. Lows around 55 at the visitor center to around 53 at the summit. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 72 at the visitor center to around 64 at the summit. Light winds. Chance of rain 20 percent.

Thursday Night: Mostly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 57 at the visitor center to around 50 at the summit. East winds up to 10 mph. Chance of rain 50 percent.

East Maui

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows around 75 near the shore to around 59 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 50 percent.

Thursday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 82 near the shore to around 71 near 5000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows around 75 near the shore to around 60 near 5000 feet. East winds up to 10 mph. Chance of rain 60 percent.

Lanai City

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Lows 68 to 73. Northeast winds 10 to 20 mph.

Thursday: Mostly sunny. Highs 78 to 84. Northeast winds up to 15 mph in the morning becoming light.

Thursday Night: Partly cloudy. Isolated showers after midnight. Lows around 71. Light winds. Chance of rain 20 percent.

Kaunakakai

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Lows 63 to 78. Northeast winds 10 to 15 mph decreasing to up to 15 mph after midnight.

Thursday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 77 to 90. Northeast winds up to 10 mph. Chance of rain 40 percent.

Thursday Night: Partly cloudy with isolated showers in the evening, then mostly cloudy with scattered showers after midnight. Lows 65 to 79. Northeast winds up to 10 mph in the evening becoming light. Chance of rain 40 percent.

Detailed Forecast

Synopsis

Trade winds weaken today into the latter half of the week as a trough passes northeast of the islands. The trough also brings an increase in moisture that will produce an uptick in shower activity through Friday. This weekend, trade winds restrengthen.

Discussion

Trades weaken today through Friday as a trough approaches and passes just north of the state Thursday night into Friday. The trough will bring additional moisture across the islands, but with lighter trades will increase precipitation chances for leeward areas during the afternoons with the development of a sea/land breeze pattern.
The winds are expected to strengthen and shift easterly late Friday into Saturday, which will focus clouds and showers windward and mauka.
For Sunday and Monday, tropical moisture is expected to be in the vicinity of the state due to the potential development of a tropical system. Most guidance keeps the track of the potential tropical system south of the islands. While there remains uncertainty in the forecast since the system has yet to develop, precipitation chances have been increased for early next week. Please continue to monitor the forecast as it is subject to change as we get closer to the weekend and details surrounding the forecast become clearer.

Aviation

Moderate trades expected through tomorrow. Some windward and mauka SHRA possible with isol MVFR conds. VFR conditions should prevail.
No AIRMETs are currently in effect.

Marine

High pressure far northeast of the waters will remain nearly stationary and slowly weaken for the next couple of days. A trough to the east of the islands will pass northeast of the islands as trade winds continue a weakening trend, becoming light and variable for most waters by Thursday as daytime sea breezes and overnight land breezes become established. By late Friday, moderate to locally fresh trades will begin to build back into the region as the high drifts southward closer to the island chain. Heading into the weekend, the potential development of a tropical system southeast of the islands is possible but uncertainty remains as the system has yet to develop.
Surf along south facing shores will continue declining through midweek as south swell fades. Another long period south swell generated from gales just south and east of New Zealand will begin arriving late this week. Surf along east facing shores will also continue to fade as background flow becomes weaker. North facing shores will remain tiny throughout the week.

Fire weather

Trade winds will weaken today through Friday, increasing chances of showers for the leeward side of the islands. Trade winds increase over the weekend with showers switching to windward. The inversion is 6000 to 7000 ft.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov