Hilo

Rest Of Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 82 near the shore to 64 to 69 at 4000 feet. Northwest winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 64 near the shore to around 50 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Thursday: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs around 80 near the shore to 64 to 69 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 30 percent.

Kona

Rest Of Today: Mostly sunny. Isolated showers in the afternoon. Highs 79 to 84 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows 64 to 70 near the shore to around 51 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 79 to 84 near the shore to around 70 near 5000 feet. West winds up to 10 mph. Chance of rain 30 percent.

Waimea

Rest Of Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 81 near the shore to 71 to 77 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 63 near the shore to 49 to 57 near 3000 feet. East winds up to 10 mph. Chance of rain 40 percent.

Thursday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs around 79 near the shore to 70 to 77 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 30 percent.

Kohala

Rest Of Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 81 near the shore to 71 to 77 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 63 near the shore to 49 to 57 near 3000 feet. East winds up to 10 mph. Chance of rain 40 percent.

Thursday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs around 79 near the shore to 70 to 77 near 3000 feet. Northeast winds up to 10 mph. Chance of rain 30 percent.

South Big Island

Rest Of Today: Mostly sunny. Isolated showers in the afternoon. Highs around 82 near the shore to around 71 near 5000 feet. Northeast winds up to 10 mph shifting to the south in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 66 near the shore to around 50 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 82 near the shore to around 71 near 5000 feet. West winds up to 10 mph. Chance of rain 30 percent.

Puna

Rest Of Today: Sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 82 near the shore to 64 to 69 at 4000 feet. Northwest winds up to 10 mph shifting to the northeast in the afternoon. Chance of rain 30 percent.

Tonight: Mostly cloudy with scattered showers. Lows around 64 near the shore to around 50 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 40 percent.

Thursday: Mostly sunny with scattered showers in the morning, then partly sunny with isolated showers in the afternoon. Highs around 80 near the shore to 64 to 69 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 30 percent.

Waikoloa

Rest Of Today: Mostly sunny. Isolated showers in the afternoon. Highs around 81 near the shore to 65 to 72 above 4000 feet. East winds up to 10 mph shifting to the northwest in the afternoon. Chance of rain 20 percent.

Tonight: Partly cloudy with isolated showers. Lows around 68 near the shore to 46 to 54 above 4000 feet. Southeast winds up 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 around 81 near the shore to 65 to 72 above 4000 feet. East winds up to 10 mph shifting to the northwest in the afternoon. Chance of rain 30 percent.

Detailed Forecast

Synopsis

Light winds will prevail through the period, allowing for daytime sea breezes and overnight land breezes in most areas, with a brief period of light trade winds expected tonight into Thursday for the eastern islands. A few showers will move onshore in the southwest flow early this morning, with the shower focus shifting to the island interiors this afternoon. Drier conditions are expected Thursday and Friday with a few showers possible over the island interiors during the day and near the coast at night. A weakening front could bring a slight increase in showers as it moves over parts of the island chain this weekend.

Discussion

Currently at the surface, a weakening cold front is located around 170 miles northwest of Kauai, while a 1029 mb high is centered around 1750 miles northeast of the Big Island. The resulting gradient is producing a light background south to southwest winds across the island chain early this morning, with land breezes prevailing statewide. Infrared satellite imagery shows mostly cloudy conditions across Oahu and Maui County, withe clear to partly cloudy skies over Kauai and the Big Island. Radar imagery shows scattered showers moving into Oahu and Maui County, with rain free conditions over Kauai and the Big Island. Main short term concern continues to revolve around rain chances the next few days.
A cold front approaching from the northwest will stall out northwest of the islands today then gradually dissipate tonight. As a result, light winds will prevail with sea breezes expected to develop statewide. A weak high will pass quickly by to the north of the state tonight and Thursday, bringing a return of light to moderate trades to the eastern islands, while land and sea breezes remain common over the western end of the state. The trades will ease Thursday night as a new cold front approaches from the northwest, with winds becoming light and variable on Friday. Light westerly winds are forecast to develop Friday night in advance of the front, then shift around to the north and northeast at light to locally moderate levels on Saturday. The winds will ease Saturday night, with land and sea breezes prevailing Sunday through early next week.
As for the remaining weather details, scattered showers will likely continue to move onshore early this morning, with a more stable and lighter wind regime reducing shower coverage for this afternoon with the focus over the island interiors. The airmass will continue to dry out and stabilize tonight, with a few showers over north and northeast facing slopes in coasts as light trades return. Fairly dry conditions are then expected Thursday through early next week, with perhaps a slight increase in shower coverage Saturday through Sunday as a front moves into the smaller islands, stalls out and dissipates.

Aviation

Light south to southwest winds are producing bands of clouds and showers over the central Hawaiian Islands from Oahu to Maui. In the short term, expect increasing shower trends over these islands this morning with brief MVFR conditions possible within these moderate to heavy shower bands. Cloud and shower activity will decrease in coverage today as more stable air moves into the region.
A weakening cold front approaching Kauai from the west will keep light winds in the forecast across the region today. These light large scale winds will allow land and sea breezes to develop over each island causing more variability in wind directions.
AIRMET Sierra for mountain obscuration is currently in effect for Oahu this morning. These conditions will diminish later this morning. No other AIRMETs in effect.

Marine

As a cold front to the west of the state lifts northeast and north of the islands, generally gentle south to southwest breezes will further weaken to light and variable through the day. A high passing to the north of the area will allow for the brief return of gentle north to northeast trade wind flow tonight through Thursday. Upper ridging to the east will have enough of an influence over the region to support a stable air mass and ultimately drier weather the latter half of the week. Another cold front may reach the far northern offshore waters this weekend and veer winds back around to the north. The passage of a couple of large northwest swells will assist in producing significant seas equal to or greater than the 10 foot Small Craft Advisory threshold over more exposed, windward waters through Thursday afternoon and then again this weekend.
A moderate size, long period north swell arrived yesterday with a moderate to large northwest swell following on this swell's heels. This northwest swell is hitting the far northwest buoys early this morning (8-9 foot, 16 second period) and should reach Kauai's north and west facing shores later this morning and Oahu's north and west shores by this evening. This north and northwest swell combination will generate High Surf Advisory (HSA) surf along Kauai and Oahu's north and west facing shores through Thursday. HSA conditions may be possible along the north facing shores of Molokai and Maui Thursday. A long fetch will develop far northwest of the islands later this week. This will push in an even larger northwest swell this weekend. This swell has a decent probability of producing warning level XL-size surf along most north and west facing shorelines this weekend.

HFO Watches/Warnings/Advisories

High Surf Advisory until 6 PM HST Thursday for Niihau, Kauai Leeward, Waianae Coast, Oahu North Shore, Olomana, Kauai North, Koolau Windward.
Small Craft Advisory from 6 PM this evening to 6 PM HST Thursday for Kauai Northwest Waters, Kauai Windward Waters, Kauai Leeward Waters, Kauai Channel, Oahu Windward Waters, Kaiwi Channel, Maui County Windward Waters.

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Data Courtesy of NOAA.gov