Hilo

Today: 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. Northeast winds up to 15 mph. Chance of rain 90 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.

Sunday: Mostly cloudy. Occasional showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 82 near the shore to 68 to 73 at 4000 feet. Northeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain 80 percent.

Kona

Today: 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.

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy after midnight. Lows 69 to 74 near the shore to around 55 near 5000 feet. Light winds. Chance of rain 50 percent.

Sunday: Mostly sunny in the morning, then mostly cloudy with showers likely and slight chance of thunderstorms 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 70 percent.

Waimea

Today: Mostly cloudy. Windy. Occasional showers 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 90 percent.

Tonight: Mostly cloudy. Windy. Showers likely in the evening, then scattered showers after midnight. Lows around 68 near the shore to 56 to 62 near 3000 feet. East winds 10 to 30 mph decreasing to up to 25 mph after midnight. Chance of rain 70 percent.

Sunday: Mostly cloudy. Breezy. Scattered showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 80 near the shore to 68 to 78 near 3000 feet. East winds up to 25 mph increasing to 15 to 25 mph in the afternoon. Chance of rain 70 percent.

Kohala

Today: Mostly cloudy. Windy. Occasional showers 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 90 percent.

Tonight: Mostly cloudy. Windy. Showers likely in the evening, then scattered showers after midnight. Lows around 68 near the shore to 56 to 62 near 3000 feet. East winds 10 to 30 mph decreasing to up to 25 mph after midnight. Chance of rain 70 percent.

Sunday: Mostly cloudy. Breezy. Scattered showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 80 near the shore to 68 to 78 near 3000 feet. East winds up to 25 mph increasing to 15 to 25 mph in the afternoon. 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 85 near the shore to around 72 near 5000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Windy. Isolated showers in the evening. Lows around 70 near the shore to around 53 near 5000 feet. East winds 10 to 30 mph. Chance of rain 20 percent.

Sunday: Windy. Mostly sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 85 near the shore to around 72 near 5000 feet. East winds up to 30 mph. Chance of rain 50 percent.

Puna

Today: 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. Northeast winds up to 15 mph. Chance of rain 90 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.

Sunday: Mostly cloudy. Occasional showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 82 near the shore to 68 to 73 at 4000 feet. Northeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain 80 percent.

Waikoloa

Today: Windy. Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 85 near the shore to 69 to 75 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 shifting to the southeast up to 15 mph after midnight. Chance of rain 20 percent.

Sunday: Breezy. Mostly sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms 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 50 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 today, with showers favoring windward and mauka areas, with the Big Island seeing more showers than smaller islands. An upper level trough will pass over the islands tonight and Sunday, bringing an uptick in showers to the island chain and sending a few more showers into leeward communities. A more typical trade wind weather pattern is then expected Sunday night through Friday, with a gradual easing of the trades Tuesday through late next week.

Discussion

Currently at the surface, a 1031 mb high is centered around 1100 miles north of Honolulu, and is driving breezy to locally windy trades across the island chain this evening. Infrared satellite imagery shows low clouds moving into windward slopes and coasts, with some high clouds streaming over the state as well. Partly to mostly cloudy conditions prevail in windward areas, with partly cloudy skies in most leeward locales. Radar imagery shows scattered showers moving windward sections of Kauai and Maui, numerous showers moving into windward Big Island, and very little shower activity elsewhere at the moment. Main short term focus continues to revolve around trade wind trends and rain chances.
High pressure north of the islands will keep breezy to locally windy conditions in place through Independence Day. Winds will be strongest today, where some of the windier areas of Maui County and the Big Island will see winds reach advisory levels at times. In fact, winds at Kohala Ranch have been blowing at advisory levels for the past several hours, with a peak wind gust of 56 mph measured at 125 AM. Additionally, several other observation sites on Lanai, leeward west Maui, and the Maui central valley have been flirting with Wind Advisory speeds through much of the night. With little change in the strength of the winds expected today, the Wind Advisory has been extended through 6 PM this evening. The gradient should relax just a bit tonight, but breezy conditions are expected to continue through the remainder of the Holiday weekend. A couple fronts will slide southward well to the north of the islands early next week, and this should result in an easing of the trades beginning Tuesday, with a further easing into the moderate range expected Wednesday through Friday.
As for the remaining weather details, a trough aloft will approach the islands from the southeast today, focusing the deeper moisture over the eastern end of the state. This should keep a showery trade wind pattern in place for the Big Island and Maui this morning. Shower weather should continue over windward Big Island this afternoon, and some leeward shower development is expected as well. Meanwhile, shower activity should decrease to minimal levels on Maui this afternoon. A fairly dry trade wind pattern should hold in place on Oahu through the day, while a band of low clouds and showers currently tracking toward Kauai, should bring an uptick in shower activity here today.
The trough aloft will dampen out as it lifts northwestward through the islands tonight and Sunday, but will drag some deeper moisture northward and into smaller islands. As a result, we should see an increase in trade wind showers statewide tonight and Sunday. The brunt of the shower activity should continue to focus over windward and mauka areas, however with the increase in deeper moisture, 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 Sunday night through late next week, but drier boundary layer conditions will overspread the state. This should bring a return of more typical summertime trade wind conditions with passing light showers moving through the islands, particularly at night and during the early morning hours, with a stray shower reaching leeward areas from time to time.

Aviation

Strong high pressure north of the state will bring breezy to locally windy easterly trades through the forecast period. This regime will help to concentrate most shower activity along the windward coasts and slopes…especially for Maui and Hawaii counties. There will be periods of MVFR ceilings and visibility associated with any of the heavier showers. Expect isolated activity elsewhere.
AIRMET Tango remains in effect for moderate low-level turbulence downwind of the higher terrain of all islands.
AIRMET Sierra remains in effect for north through east portions of the Big Island and Maui above 2500 feet due to tempo mountain obscuration from low clouds and showers.

Marine

Robust high pressure far north of the area will sustain fresh to strong trade winds across most of the state's coastal waters into next week. Winds are expected to reach 30 knots, or near gale force, in the Alenuihaha Channel and the waters south of the Big Island. Threshold seas of 10 feet are also likely in those zones through Saturday. Currently, a Small Craft Advisory is posted for all coastal waters through Sunday afternoon. Winds will likely stay elevated across most coastal waters into Monday, then scaling back to the typically windier waters around Maui County and the Big Island Tuesday into Wednesday.
No significant swells are expected along all shores into next week. The strong trades will support rough and choppy surf along east facing shores, but surf will likely stay below the advisory threshold of 10 feet. The current small south swell will continue to lower. Only very small, medium period, background south and southeast swells are expected into next week.

HFO Watches/Warnings/Advisories

Wind Advisory until 6 PM HST this evening for Lanai Mauka, Kahoolawe, Maui Windward West, Maui Leeward West, 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