Hilo

Tonight: Mostly cloudy with scattered showers. Lows 64 to 71 near the shore to 54 to 59 at 4000 feet. North winds up to 10 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 79 to 86 near the shore to 65 to 71 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Wednesday Night: Mostly cloudy with scattered showers. Lows 64 to 71 near the shore to around 58 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Kona

Tonight: Partly cloudy with isolated showers in the evening, then clear after midnight. Lows around 75 near the shore to around 53 near 5000 feet. Northwest winds up to 10 mph in the evening becoming light. Chance of rain 20 percent.

Wednesday: Mostly sunny. Isolated showers in the afternoon. Highs 83 to 88 near the shore to around 69 near 5000 feet. Light winds becoming west around 10 mph in the afternoon. Chance of rain 20 percent.

Wednesday Night: Partly cloudy. Lows 72 to 77 near the shore to 51 to 56 near 5000 feet. Northwest winds up to 10 mph in the evening becoming light.

Waimea

Tonight: Partly cloudy with scattered showers. Lows 64 to 72 near the shore to 56 to 63 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny. Isolated showers in the afternoon. Highs 66 to 86. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday Night: Partly cloudy with isolated showers. Lows 64 to 72 near the shore to 57 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Kohala

Tonight: Partly cloudy with scattered showers. Lows 64 to 72 near the shore to 56 to 63 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny. Isolated showers in the afternoon. Highs 66 to 86. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday Night: Partly cloudy with isolated showers. Lows 64 to 72 near the shore to 57 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

South Big Island

Tonight: Mostly clear. Lows around 75 near the shore to around 55 near 5000 feet. East winds 10 to 15 mph.

Wednesday: Mostly sunny. Isolated showers in the afternoon. Highs around 85 near the shore to around 69 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Wednesday Night: Partly cloudy. Lows around 75 near the shore to around 55 near 5000 feet. East winds 10 to 15 mph.

Puna

Tonight: Mostly cloudy with scattered showers. Lows 64 to 71 near the shore to 54 to 59 at 4000 feet. North winds up to 10 mph. Chance of rain 50 percent.

Wednesday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 79 to 86 near the shore to 65 to 71 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Wednesday Night: Mostly cloudy with scattered showers. Lows 64 to 71 near the shore to around 58 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Waikoloa

Tonight: Mostly clear. Lows around 75 near the shore to around 55 above 4000 feet. East winds 10 to 15 mph.

Wednesday: Sunny. Highs 84 to 91 near the shore to 67 to 75 above 4000 feet. East winds 10 to 15 mph shifting to the north in the afternoon.

Wednesday Night: Partly cloudy. Lows around 75 near the shore to around 57 above 4000 feet. Northeast winds 10 to 15 mph.

Detailed Forecast

Synopsis

Moderate to locally breezy trade winds will continue for the next couple of days, with lighter east to southeast winds expected over the weekend. Limited rainfall is expected, with brief showers favoring windward areas, with some afternoon showers over the Big Island's leeward slopes.

Discussion

A surface ridge along 35N will support moderate to locally breezy trade winds for the next couple of days. By the end of the week, developing low pressure along will force the ridge southward toward the islands, leading to lighter E to SE winds, especially for Kauai and Oahu. The fast-moving low will move far NE of the area late in the weekend, and the ridge will rebound northward, leading to a return of moderate to breezy trade winds by Monday.
A mid-level ridge will build over the islands from the E the next couple of days, then remain in place through the weekend. End result will be a relatively dry weather pattern, with brief showers favoring windward areas, especially night and morning. High clouds will gradually diminish over the next day or so as the ridge arrives.

Aviation

Moderate to locally breezy trade winds will continue through the week. The air mass will become increasingly dry and stable over the next few days. Infrequent bands of light trade wind showers will impact mainly windward slopes and coasts. Scattered light showers are possible over the upper elevations of the Big Island in the late afternoon and evening hours. Expect VFR conditions to prevail all areas.
No AIRMETs are currently in effect and none are anticipated at this time.

Marine

High pressure far north of the state will maintain moderate to locally strong trade winds over the next few days. A Small Craft Advisory remains in effect for the typical windy waters around Maui County and the Big Island. Trade winds should hold around the moderate to locally strong speeds through Friday then gradually decline over the weekend as the high weakens in response to a front passing far north of the state. For the offshore waters, a trough located far SW of the state will bring a slight chance of thunderstorms over the west and SW waters through tonight.
A moderate long period northwest swell (320 to 330 degrees) filled in throughout the day today and should peak tonight then steadily decline the rest of the work week. Buoy 51001 and 51101 northwest of Kauai showed a peak swell height of around 6 to 7 feet 16 seconds earlier today. This should translate to surf peaking below advisory thresholds tonight for north facing shores of Kauai and Oahu. A smaller north-northwest swell should provide a boost this weekend.
Surf along south facing shores should see a series of small long- period southwest pulses through the weekend due to a series of storms near the Tasman Sea last week. The first pulse is peaking today with another small long-period southwest swell possible Friday into the weekend. Additionally, a fetch of strong southwest winds near 10N170W yesterday should bring an increase of short- period energy from the southwest Wednesday into Thursday. East facing shores should remain small through much of the week due to the lack of strong trades locally or upstream of the state.

Fire weather

KBDI values are greater than 600, and minimum RH values will likely near 45% again tomorrow afternoon. Sustained winds at PHNL will likely remain below the 20 mph criteria for a Red Flag Warning, indicating that critical fire weather conditions are not expected. However, many leeward areas are in moderate to severe drought, and the fire weather threat is elevated.

HFO Watches/Warnings/Advisories

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

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Data Courtesy of NOAA.gov