Hilo

Today: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 84 near the shore to 69 to 74 at 4000 feet. North winds up to 20 mph shifting to the northeast 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy with occasional showers. Lows around 68 near the shore to around 54 at 4000 feet. North winds up to 15 mph. Chance of rain 90 percent.

Saturday: Mostly cloudy. Occasional showers in the morning, then showers likely in the afternoon. Highs around 83 near the shore to 68 to 73 at 4000 feet. North winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 90 percent.

Kona

Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 82 to 87 near the shore to around 69 near 5000 feet. West winds up to 10 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 69 to 74 near the shore to around 55 near 5000 feet. Light winds. Chance of rain 20 percent.

Saturday: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs 81 to 86 near the shore to around 68 near 5000 feet. West winds up to 10 mph. Chance of rain 50 percent.

Waimea

Today: Windy. Partly sunny with scattered showers. Highs around 82 near the shore to 69 to 79 near 3000 feet. East winds 10 to 30 mph increasing to 20 to 30 mph in the afternoon. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with showers likely. Lows around 68 near the shore to 56 to 62 near 3000 feet. East winds 10 to 30 mph. Chance of rain 70 percent.

Saturday: Partly sunny. Windy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to 68 to 78 near 3000 feet. East winds 10 to 30 mph. Chance of rain 70 percent.

Kohala

Today: Windy. Partly sunny with scattered showers. Highs around 82 near the shore to 69 to 79 near 3000 feet. East winds 10 to 30 mph increasing to 20 to 30 mph in the afternoon. Chance of rain 50 percent.

Tonight: Windy. Mostly cloudy with showers likely. Lows around 68 near the shore to 56 to 62 near 3000 feet. East winds 10 to 30 mph. Chance of rain 70 percent.

Saturday: Partly sunny. Windy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 81 near the shore to 68 to 78 near 3000 feet. East winds 10 to 30 mph. Chance of rain 70 percent.

South Big Island

Today: Windy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 86 near the shore to around 73 near 5000 feet. East winds up to 30 mph increasing to 10 to 30 mph in the afternoon. Chance of rain 20 percent.

Tonight: Windy. Partly cloudy with isolated showers. Lows around 70 near the shore to around 53 near 5000 feet. Northeast winds 10 to 30 mph. Chance of rain 20 percent.

Saturday: Windy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 85 near the shore to around 72 near 5000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Puna

Today: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs around 84 near the shore to 69 to 74 at 4000 feet. North winds up to 20 mph shifting to the northeast 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Tonight: Mostly cloudy with occasional showers. Lows around 68 near the shore to around 54 at 4000 feet. North winds up to 15 mph. Chance of rain 90 percent.

Saturday: Mostly cloudy. Occasional showers in the morning, then showers likely in the afternoon. Highs around 83 near the shore to 68 to 73 at 4000 feet. North winds up to 15 mph shifting to the northeast in the afternoon. Chance of rain 90 percent.

Waikoloa

Today: Mostly sunny. Windy. Isolated showers in the afternoon. Highs around 86 near the shore to 70 to 76 above 4000 feet. Northeast winds up to 30 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows around 72 near the shore to 51 to 58 above 4000 feet. East winds up to 25 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 85 near the shore to 69 to 75 above 4000 feet. Northeast winds up to 25 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

High pressure north of the state will keep breezy to locally windy conditions in place through the 4th of July Holiday weekend. Fairly typical trade wind weather will prevail through Saturday, with showers favoring windward and mauka areas, with the eastern islands seeing more showers than the western end of the state. An upper level trough will pass over the islands Saturday night through Sunday night, bringing an uptick in showers to windward and mauka areas, and sending a few showers into leeward communities. A more typical trade wind weather pattern is then expected from Independence Day through next Friday, with a gradual easing of the trades during the middle to latter part of next week.

Discussion

Currently at the surface, a 1031 mb high is centered around 1000 miles north of Honolulu, and is driving breezy to locally windy trades across the island chain early this morning. Infrared satellite imagery shows low clouds moving into windward slopes and coasts, with some high clouds streaming over the islands as well. Mostly cloudy conditions prevail in most windward areas, with partly cloudy skies in most leeward locales. Radar imagery shows scattered showers moving into windward areas, with a few showers or sprinkles spilling over into leeward communities. Main short term focus revolves around trade wind trends and rain chances.
High pressure north of the islands will keep breezy to locally windy conditions in place through Tuesday. Winds will be close to advisory levels at times over the typically windy areas of Maui County and the Big Island through the 4th of July Holiday weekend. A Wind Advisory has been issued for these areas through 6 PM this evening, but may need to be extended into the weekend. The trades should ease into the moderate to locally breezy range Wednesday through the end of the work week as the high weakens.
As for the remaining weather details, fairly typical trade wind weather will prevail over Maui County and the Big Island during the next couple days, while drier trade wind conditions hold in place over Kauai and Oahu. A trough aloft along with some deeper moisture will move into the islands Saturday night then gradually dampen out as it lifts northwestward across the state Sunday and Sunday night. This should increase trade wind showers statewide, and although the brunt of the shower activity should continue to focus over windward and mauka areas, a few more showers should reach leeward communities. Additionally, conditions may destabilize enough to allow for a thunderstorm or two Sunday afternoon on the Big Island. Weak troughing aloft is forecast to linger over the islands from Independence Day through late next week, and this will likely keep a fairly typical summertime trade wind regime in place.
The Wind Advisory for the Haleakala summit had been extended through 6 PM this evening. This may need to be extended through tonight, but will let the day crew monitor observations and reassess for the afternoon forecast package.
Winds may pick up close to advisory levels on the Big Island summits during the next couple days as well, so we will continue to monitor this for the need for an advisory.

Aviation

Trade winds will be moderate to breezy, and locally strong, as robust high pressure remains far north of the area. Showers and any accompanying MVFR conditions in lower ceilings and visibilities will mainly affect windward and mauka sections across the state, with afternoon and early evening cloud buildups over leeward Big Island as well. VFR, however, will predominate in most areas most of the time.
AIRMET Tango remains in effect for moderate low-level turbulence downwind of the higher terrain of all islands.

Marine

A large, strong area of surface high pressure approximately 1,000 miles north of the islands is producing a very tight pressure pressure gradient back toward the state. This is resulting in ASCAT-verified sustained 20 to 25 knot trade winds across many local coastal and offshore water zones. Trade magnitudes reaching, or slightly exceeding, 30 knots are possible through island bays, channels and waters south of Big Island the next several days. These fresh to locally strong trades will persist into early next week with little to no weakening. A Small Craft Advisory (SCA) for winds is in effect for all waters through Sunday afternoon. These stronger winds have created rough seas and the long duration of these winds will maintain a higher east wind wave chop. While many zones will remain under SCA threshold 10 foot seas, seas within the Alenuihaha Channel and south of Big Island may approach and reach this SCA criteria the next few days.
The current diminishing south swell will fade through the day. Only a medium period background south or southeast swell is expected into next week. As mentioned above, fresh to strong trades over and upstream of the state will produce elevated east wind waves that, with an underlying short period easterly swell, will produce rough seas as this elevated chop impacts many eastern facing shores. No significant swell from any distant source is expected the next several days.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 PM HST this evening for Lanai Mauka, Kahoolawe, Maui Windward West, Maui Leeward West, Haleakala Summit, Kohala, Big Island Interior, Lanai Windward, Lanai Leeward, Lanai South, Maui Central Valley North, Maui Central Valley South, Windward Haleakala, South Haleakala, Big Island North.
Small Craft Advisory until 6 PM HST Sunday for all Hawaiian waters,

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Data Courtesy of NOAA.gov