Hilo

Today: Partly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. North winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with numerous showers. Lows around 70 near the shore to around 56 at 4000 feet. North winds up to 15 mph. Chance of rain 70 percent.

Monday: Partly sunny with scattered showers. Highs around 87 near the shore to 70 to 76 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Kona

Today: Mostly sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 83 to 88 near the shore to around 70 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows around 73 near the shore to around 57 near 5000 feet. Light winds. Chance of rain 20 percent.

Monday: Mostly sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 83 to 88 near the shore to around 70 near 5000 feet. West winds up to 10 mph. Chance of rain 40 percent.

Waimea

Today: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 84 near the shore to 70 to 81 near 3000 feet. East winds 10 to 25 mph. Chance of rain 40 percent.

Tonight: Breezy. Partly cloudy with scattered showers. Lows around 70 near the shore to 58 to 64 near 3000 feet. East winds 10 to 25 mph decreasing to up to 25 mph after midnight. Chance of rain 50 percent.

Monday: Breezy. Mostly sunny with scattered showers. Highs around 85 near the shore to 70 to 81 near 3000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 40 percent.

Kohala

Today: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs around 84 near the shore to 70 to 81 near 3000 feet. East winds 10 to 25 mph. Chance of rain 40 percent.

Tonight: Breezy. Partly cloudy with scattered showers. Lows around 70 near the shore to 58 to 64 near 3000 feet. East winds 10 to 25 mph decreasing to up to 25 mph after midnight. Chance of rain 50 percent.

Monday: Breezy. Mostly sunny with scattered showers. Highs around 85 near the shore to 70 to 81 near 3000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 40 percent.

South Big Island

Today: Breezy. Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 87 near the shore to around 74 near 5000 feet. East winds 10 to 25 mph. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with isolated showers in the evening, then partly cloudy after midnight. Lows around 72 near the shore to around 55 near 5000 feet. Northeast winds 10 to 25 mph. Chance of rain 20 percent.

Monday: Breezy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 87 near the shore to around 74 near 5000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 20 percent.

Puna

Today: Partly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. North winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 50 percent.

Tonight: Mostly cloudy with numerous showers. Lows around 70 near the shore to around 56 at 4000 feet. North winds up to 15 mph. Chance of rain 70 percent.

Monday: Partly sunny with scattered showers. Highs around 87 near the shore to 70 to 76 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 50 percent.

Waikoloa

Today: Mostly sunny. Breezy. Highs around 87 near the shore to 71 to 77 above 4000 feet. Northeast winds up to 25 mph.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows around 74 near the shore to 53 to 60 above 4000 feet. East winds up to 25 mph. Chance of rain 20 percent.

Monday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 87 near the shore to 71 to 77 above 4000 feet. Northeast winds up to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

High pressure northwest of the state will support moderate to breezy trade winds through the middle of the week. Fairly typical trade wind weather is expected during this time, with mainly windward and mauka showers and the occasional leeward spillover. The trades are expected to ease for the tail end of the upcoming work week into next weekend, with the potential for an increase in showers as a disturbance aloft pivots southward over the islands, while the remnant trough of tropical cyclone Jova approaches from the east.

Discussion

Currently at the surface, a 1027 mb high is centered around 1300 miles north-northwest of Kauai, with a 1022 mb high around 1650 miles northeast of Honolulu. The resulting gradient is producing moderate trade winds across the island chain early this morning. Infrared satellite imagery shows partly to mostly cloudy conditions in windward areas, with clear to partly cloudy skies in most leeward locales. Meanwhile, radar imagery shows scattered showers moving into windward slopes and coasts, with some of these showers spilling over into leeward communities. Main short term focus revolves around trade wind trends and rain chances.
The high to the distant northwest will remain anchored northwest of the state through the middle of the week, keeping moderate to breezy trades blowing across the island chain. A front approaching from the northwest and the remnant trough of tropical cyclone Jova approaching from the east, should ease the trade winds back into the light to moderate range for the tail end of the upcoming work week and into next weekend.
As for the remaining weather details, fairly typical trade wind weather will prevail through the middle of the week, with bands of clouds and showers moving through the islands from time to time, favoring primarily windward and mauka locations, with the occasional shower reaching leeward communities. We could see an increase in trade wind shower coverage and intensity toward the tail end of the upcoming work week and into next weekend, as troughing aloft pivots southward over the state, while the remnant trough of tropical cyclone Jova approaches and eventually moves through the islands from east to west.

Aviation

Moderate to locally breezy trades will persist through twenty-four hours and beyond. Clouds and scattered showers will favor windward and mauka areas with isolated spillover showers impacting leeward areas at times. Brief MVFR ceilings and visibilities are possible in passing showers, otherwise VFR conditions will prevail statewide.
AIRMET TANGO for moderate low level turbulence remain in effect. Conditions are expected to persist through twenty-four hours and beyond.

Marine

A high far northwest of the main Hawaiian Islands will push southeastward over the next few days, strengthening the ridge north of the state. This will keep trade wind speeds in the moderate to locally strong range through the first half of the work week. A Small Craft Advisory (SCA) remains in effect for the typical windier waters around Maui County and the Big Island through Tuesday afternoon.
Surf along south facing shores will get a boost over the next few days as a small, long-period south swell fills in. The swell and surf are forecast to peak Monday slightly above the summer average, then gradually decline through the middle of the week.
Strengthening trade winds, along with a small to moderate, long- period east swell from Tropical Storm Jova in the East Pacific, will boost east shore surf heights through the middle of the week. A High Surf Advisory (HSA) for east facing shores is not expected at this time, but will continue to monitor the nearshore buoys as this swell unfolds.

HFO Watches/Warnings/Advisories

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

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Data Courtesy of NOAA.gov