West Side

Tonight: Breezy. Partly cloudy with isolated showers. Lows 67 to 74. Northeast winds 10 to 20 mph shifting to the east after midnight. Chance of rain 20 percent.

Thursday: Breezy. Partly sunny with isolated showers. Highs 78 to 84. East winds up to 20 mph shifting to the northeast 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Thursday Night: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 67 to 74. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

South Side

Tonight: Partly cloudy. Lows 67 to 75. North winds up to 15 mph.

Thursday: Mostly sunny. Highs around 87. North winds up to 15 mph.

Thursday Night: Partly cloudy. Lows 67 to 75. North winds 10 to 15 mph.

North Shore

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 71 near the shore to around 51 near 5000 feet. Southeast winds 10 to 20 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Thursday: Mostly cloudy. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 77 to 83 near the shore to around 65 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows around 71 near the shore to around 52 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Central Maui

Tonight: Breezy. Partly cloudy with isolated showers. Lows 66 to 71. East winds 10 to 20 mph decreasing to up to 15 mph after midnight. Chance of rain 20 percent.

Thursday: Partly sunny. Breezy. Isolated showers in the morning. Highs 81 to 87. Northeast winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Thursday Night: Mostly cloudy in the evening, then partly cloudy with isolated showers after midnight. Lows 67 to 72. Northeast winds 10 to 15 mph. Chance of rain 20 percent.

Upcountry

Tonight: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows around 46 at the visitor center to around 49 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers. Highs around 60 at the visitor center to around 68 at the summit. East winds up to 20 mph. Chance of rain 50 percent.

Thursday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 43 to 54. East winds 10 to 15 mph. Chance of rain 50 percent.

East Maui

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 71 near the shore to around 51 near 5000 feet. Southeast winds 10 to 20 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Thursday: Mostly cloudy. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 77 to 83 near the shore to around 65 near 5000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Thursday Night: Mostly cloudy with scattered showers. Lows around 71 near the shore to around 52 near 5000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Lanai City

Tonight: Partly cloudy. Breezy. Lows around 65. Northeast winds 10 to 20 mph decreasing to up to 15 mph after midnight.

Thursday: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 71 to 80. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 20 percent.

Thursday Night: Mostly cloudy in the evening then becoming partly cloudy. Lows around 65. Light winds becoming northeast around 10 mph after midnight.

Kaunakakai

Tonight: Partly cloudy. Breezy. Isolated showers after midnight. Lows 58 to 73. East winds 10 to 20 mph. Chance of rain 20 percent.

Thursday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny in the afternoon. Highs 69 to 87. East winds 10 to 20 mph. Chance of rain 40 percent.

Thursday Night: Partly cloudy. Isolated showers in the evening, then scattered showers after midnight. Lows 59 to 73. East winds 10 to 15 mph. Chance of rain 40 percent.

Detailed Forecast

Synopsis

A slight increase of passing showers are expected tonight through Friday morning with drier weather conditions expected Friday afternoon into the weekend. Trade winds should begin to gradually ease over the next few days with moderate trades expected by the weekend.

Discussion

Latest satellite imagery shows a line of cumulus clouds located just outside of the coastal waters this afternoon. This line of clouds should move in later tonight and will likely bring an increase of showers over windward and mauka areas with some showers making its way over leeward areas due to the breezy trade winds. Scattered showers should continue to persist off and on through Friday morning with even a possibility of some isolated downpours especially over the western half of the state Thursday night due to a weak upper level trough to our west. A drier airmass in low levels should move in by Friday afternoon, which should bring a decrease of showers. Generally though, rainfall intensities should remain light for the most part.
The breezy trade winds will likely weaken just a hair by Thursday and decrease a little bit more into the moderate speeds Friday through the weekend.
Over the weekend, mostly fair weather is expected with moderate trade winds. Trade winds should be light enough for localized sea breezes at select leeward areas during the afternoons, which could bring an increase of clouds and some showers.

Aviation

GOES-W Day Cloud Phase Distinction product showing band of SCT to BKN showery clouds riding in on the trades beyond about 40 nm from shore. Based on extrapolation and high res guidance, these will bring tempo MVFR SHRA mainly after dark to the usual windward and mauka portions of the state overnight. Not likely, but possible we may need AIRMET SIERRA for mtn obsc along some N and E slopes for a while overnight.
Trades breezy enough that few -SHRA could make it over to interior or leeward sections of the smaller islands overnight as well. Also could see ISOL MVFR in nighttime SHRA near the Kona shore as well in the wraparound flow to the lee of the BI. Expecting improving conditions and predominantly VFR with only ISOL MVFR windward and mauka again after sunrise.
Airmet TANGO for turb S thru W of mtn will be needed into Thu with breezy trades continuing below the trade wind inversion.

Marine

Locally strong trades gradually ease Thursday becoming gentle to fresh Friday in response to weakening high pressure NE of the islands. Gentle to fresh trades prevail Friday into early next week then restrengthen as the seasonal high redevelops. Small Craft Advisory remains in effect as is.
Tiny to small long period SW swell filling in today resulting in small surf along favored exposures. Forerunners from a moderate, long period SSW swell originating from an extratropical cyclone east of New Zealand will arrive along S facing shores during Friday. This swell will peak over the weekend near the High Surf Advisory threshold before fading into early next week.
Locally strong trades maintain choppy surf along E facing shores. Meanwhile, the combination of strong high pressure NE of the islands and a low near the California coast earlier this week yields potential for a moderate, medium period NE swell to fill in Thursday afternoon and peak on Friday. Surf along N facing shores remains small.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Thursday for Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

Data Courtesy of NOAA.gov