West Side

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy after midnight. Haze after midnight. Lows 66 to 72. Light winds. Chance of rain 40 percent.

Wednesday: Mostly sunny. Haze in the morning. Isolated showers in the afternoon. Highs 78 to 83. Northeast winds up to 15 mph. Chance of rain 20 percent.

Wednesday Night: Mostly clear. Isolated showers in the evening. Lows 67 to 73. East winds up to 15 mph. Chance of rain 20 percent.

South Side

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy after midnight. Haze after midnight. Lows 64 to 74. Light winds. Chance of rain 30 percent.

Wednesday: Sunny. Haze in the morning. Highs around 86. Light winds.

Wednesday Night: Clear. Lows 65 to 75. Northwest winds up to 15 mph.

North Shore

Tonight: Mostly cloudy. Scattered showers and isolated thunderstorms in the evening, then scattered showers after midnight. Haze after midnight. Lows around 68 near the shore to around 50 near 5000 feet. Light winds becoming southeast up to 10 mph after midnight. Chance of rain 50 percent.

Wednesday: Haze in the morning. Partly sunny with scattered showers. Highs 78 to 83 near the shore to around 66 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Wednesday Night: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 69 near the shore to around 50 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 50 percent.

Central Maui

Tonight: Mostly cloudy with scattered showers and isolated thunderstorms in the evening, then partly cloudy after midnight. Haze after midnight. Lows around 66. Light winds. Chance of rain 30 percent.

Wednesday: Mostly sunny. Haze in the morning. Isolated showers in the afternoon. Highs 80 to 87. Northeast winds up to 15 mph. Chance of rain 20 percent.

Wednesday Night: Clear. Lows around 67. East winds up to 15 mph.

Upcountry

Tonight: Mostly cloudy with scattered showers and isolated thunderstorms in the evening, then partly cloudy with scattered showers after midnight. Haze after midnight. Lows around 44 at the visitor center to around 40 at the summit. Light winds becoming southeast up to 10 mph after midnight. Chance of rain 50 percent.

Wednesday: Mostly sunny. Haze in the morning. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 60 at the visitor center to around 62 at the summit. East winds up to 10 mph. Chance of rain 40 percent.

Wednesday Night: Mostly clear. Breezy. Isolated showers in the evening, then scattered showers after midnight. Lows around 45 at the visitor center to around 42 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

East Maui

Tonight: Mostly cloudy. Scattered showers and isolated thunderstorms in the evening, then scattered showers after midnight. Haze after midnight. Lows around 68 near the shore to around 50 near 5000 feet. Light winds becoming southeast up to 10 mph after midnight. Chance of rain 50 percent.

Wednesday: Haze in the morning. Partly sunny with scattered showers. Highs 78 to 83 near the shore to around 66 near 5000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Wednesday Night: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows around 69 near the shore to around 50 near 5000 feet. Southeast winds up to 15 mph. Chance of rain 50 percent.

Lanai City

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy after midnight. Haze after midnight. Lows around 63. Light winds. Chance of rain 50 percent.

Wednesday: Mostly sunny. Haze in the morning. Scattered showers in the afternoon. Highs 72 to 80. Light winds becoming northeast up to 10 mph in the afternoon. Chance of rain 30 percent.

Wednesday Night: Mostly clear. Lows around 65. Northeast winds up to 15 mph.

Kaunakakai

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Haze after midnight. Lows 55 to 71. Light winds. Chance of rain 50 percent.

Wednesday: Mostly sunny. Haze in the morning. Isolated showers in the afternoon. Highs 69 to 86. Light winds becoming east up to 15 mph in the afternoon. Chance of rain 20 percent.

Wednesday Night: Clear. Lows 57 to 73. East winds 10 to 15 mph.

Detailed Forecast

Synopsis

Light east southeast winds will allow for land breezes to develop tonight and hold into early morning Wednesday. A cold upper level low east of the state will keep a chance of locally heavy showers and a few thunderstorms through this evening, however land breezes should keep most shower activity over the coastal waters through early morning Wednesday. Light to gentle trade winds will gradually return Wednesday, providing a hybrid sea breeze trade wind pattern where leeward and interior areas may still see some clouds build up in the afternoon as well as clouds and showers focusing along windward and mauka areas. Typical breezy trade winds are expected Friday into early next week.

Discussion

Light winds continue across the state this evening as a weak surface trough extends northward from Oahu and high pressure remains far northeast of the islands. Radar and satellite imagery show the numerous moderate to locally heavy showers that have developed over island interiors this afternoon as sea breezes matured are trending down and pushing offshore as land breezes begin to develop. A deep upper level low just east of the state will begin to shift eastward and open up into a trough overnight through Wednesday. The proximity of the low this evening will keep thunderstorms in the forecast but will taper off by Wednesday. Volcanic emissions and light background east southeast flow will keep vog in place over portions of the state through tonight.
Wednesday will serve as a transition day where gentle to moderate trades will gradually build back as the surface trough dissipates west of the state. This will allow drier air to slowly filter in from the east. The airmass will also gradually become more stable as the upper level low shifts eastward and weakens, allowing a mid level ridge to build over the state. Vog will also shift away from the smaller islands and blow mostly offshore by Wednesday night.
Moderate to locally breezy trades are expected to return Friday then hold through early next week as a pair of strong high pressure systems move north of the state. Expect showers to favor windward and mauka areas, particularly during the overnight and early morning hours.

Aviation

A few heavy SHRA and isol TSRA is possible the rest of this evening. Trades return tomorrow with SHRA along windward and mauka locations. Brief periods of MVFR/IFR conds may occur with the more robust showers and storms, otherwise VFR should prevail.
AIRMET Sierra for mtn obsc is currently in effect for Maui, Lanai, and the Big Island. Conds are expected to improve later this evening.

Marine

A trough of low pressure north of the island chain will linger through the night and continue to weaken the high pressure ridge over the state, keeping light and variable winds across the region. Trades with more stable weather conditions will build back in from tomorrow onward, strengthening to Small Craft Advisory levels for the typical windier coastal waters around Maui and the Big Island by Thursday.
A small northwest swell will continue to slowly fade, allowing surf along north and west facing shores to remain near or below average levels for this time of year. By Thursday, a moderate to long period north-northwest swell is expected to arrive, producing surf above the seasonal average. This north-northwest swell will slowly decline over the weekend.
Multiple small south swells will keep elevated south shore surf heights into the weekend. Trade winds should strengthen through Friday with rough and choppy surf rising along east facing shores by this weekend.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov