West Side

Today: Mostly sunny. Scattered showers early in the morning, then isolated showers in the late morning and afternoon. Highs 76 to 82. East winds up to 15 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 66 to 74. East winds up to 15 mph. Chance of rain 40 percent.

Tuesday: Mostly sunny with scattered showers early in the morning, then partly sunny with isolated showers in the late morning and afternoon. Highs 77 to 82. West winds up to 10 mph. Chance of rain 40 percent.

South Side

Today: Mostly sunny. Highs 74 to 84. North winds up to 15 mph shifting to the northeast in the afternoon.

Tonight: Mostly clear. Isolated showers after midnight. Lows 66 to 74. North winds up to 15 mph. Chance of rain 20 percent.

Tuesday: Mostly sunny with isolated showers in the morning, then partly sunny in the afternoon. Highs 75 to 85. Light winds becoming northwest up to 10 mph in the afternoon. Chance of rain 20 percent.

North Shore

Today: Occasional showers early in the morning, then scattered showers in the late morning and afternoon. Highs around 80 near the shore to around 64 near 5000 feet. Southeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain near 100 percent.

Tonight: Mostly cloudy with scattered showers. Lows 68 to 74 near the shore to around 52 near 5000 feet. Southeast winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Tuesday: Mostly cloudy with scattered showers. Highs around 81 near the shore to around 66 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Central Maui

Today: Partly sunny early in the morning then becoming mostly sunny. Breezy. Isolated showers in the morning. Highs 78 to 84. Northeast winds up to 20 mph shifting to the east 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy until early morning then becoming mostly cloudy. Isolated showers until early morning, then scattered showers early in the morning. Lows 66 to 71. East winds up to 15 mph. Chance of rain 40 percent.

Tuesday: Partly sunny. Scattered showers early in the morning, then isolated showers in the late morning and afternoon. Highs 79 to 85. Northeast winds up to 10 mph. Chance of rain 40 percent.

Upcountry

Today: Mostly sunny. Scattered showers early in the morning, then isolated showers in the late morning and afternoon. Highs around 59 at the visitor center to around 67 at the summit. Southeast winds up to 10 mph. Chance of rain 50 percent.

Tonight: Partly cloudy with scattered showers. Lows 42 to 55. Southeast winds up to 10 mph. Chance of rain 50 percent.

Tuesday: Mostly sunny. Scattered showers early in the morning, then isolated showers in the late morning and afternoon. Highs around 61 at the visitor center to around 68 at the summit. Light winds becoming west up to 10 mph in the afternoon. Chance of rain 50 percent.

East Maui

Today: Occasional showers early in the morning, then scattered showers in the late morning and afternoon. Highs around 80 near the shore to around 64 near 5000 feet. Southeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain near 100 percent.

Tonight: Mostly cloudy with scattered showers. Lows 68 to 74 near the shore to around 52 near 5000 feet. Southeast winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Tuesday: Mostly cloudy with scattered showers. Highs around 81 near the shore to around 66 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Lanai City

Today: Breezy. Sunny early in the morning, then partly sunny with isolated showers in the late morning and afternoon. Highs 70 to 78. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Lows around 65. Northeast winds up to 15 mph in the evening becoming light.

Tuesday: Sunny early in the morning, then partly sunny with isolated showers in the late morning and afternoon. Highs 71 to 78. Light winds becoming west up to 10 mph in the afternoon. Chance of rain 20 percent.

Kaunakakai

Today: Partly sunny early in the morning then becoming mostly sunny. Breezy. Isolated showers in the morning. Highs 68 to 84. Northeast winds 10 to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 58 to 73. East winds 10 to 15 mph decreasing to up to 10 mph after midnight. Chance of rain 20 percent.

Tuesday: Mostly sunny early in the morning then becoming partly sunny. Isolated showers. Highs 70 to 85. Light winds. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Moderate easterly trade winds will persist today, with clouds and light showers favoring windward and mauka areas during the early morning hours. Trades will ease Tuesday as the surface ridge weakens, bringing a transition to light winds, increasing humidity, and land and sea breeze conditions through Thursday. Showers will remain brief and mainly over interior and leeward areas during the afternoons. Rainfall chances may increase by next weekend as an upper disturbance and a weak front approach the islands.

Discussion

Moderate easterly trades will remain in place today, with low clouds and a few light showers focused over windward and mauka areas. Leeward areas will remain mostly dry, with only isolated passing showers possible.
Beginning Tuesday, the ridge north of the islands will weaken in response to a series of cold fronts passing well north of the state. This will lead to a gradual easing of the trade winds, with local land and sea breeze circulations becoming more dominant through midweek. From Tuesday through Thursday, a more humid air mass will settle over the islands, with dewpoints potentially climbing into the mid- to upper-60s. These dewpoints combined with the afternoon sea breezes will support localized afternoon cloud buildups and a few brief showers over interior and leeward areas, followed by clearing at night as land breezes develop.
By the latter part of the week into the weekend, moisture and rainfall chances may trend up. Global guidance indicates upper heights lowering as an upper-level disturbance approaches the region. In addition, a weak attendant frontal boundary may move into the area. However, there remains considerable spread among the model solutions regarding the timing and strength of these features, so confidence in the details remains limited at this time.

Aviation

Moderate trades continue, with clouds and brief showers expected over windward sites. Periods of MVFR ceilings and visibility are possible in showers, otherwise widespread VFR is expected. Trades are expected to gradually weaken through the midweek.
AIRMET SIERRA is in effect for northern Oahu due to clouds and showers, however conditions are expected to improve by daybreak.

Marine

Moderate to locally fresh trade winds will be in place today and then weaken to land/sea breezes Tuesday and Wednesday as a front to the northwest passes by to the north and weakens the ridge. Gentle to moderate trade winds are expected to redevelop Thursday and Friday before another front passes by to the north this weekend and make winds light and variable.
A moderate northwest swell coming in a little below guidance will build today and produce surf above seasonal average during the peak tonight and early Tuesday. This swell will slowly decline late Tuesday and Wednesday. A larger northwest swell could produce surf near the High Surf Advisory level Thursday, then lower Friday into next weekend.
A south-southwest swell will gradually decrease today and Tuesday, with small pulses keeping surf from going flat for the later half of the week.
Trade wind swell will lower below seasonal average today and will remain small through the remainder of the week.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov