Hilo

Today: Mostly cloudy. Showers likely in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 83 near the shore to 69 to 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with showers likely. Lows around 68 near the shore to around 54 at 4000 feet. North winds up to 15 mph. Chance of rain 70 percent.

Independence Day: Partly sunny. Breezy. Showers likely in the morning, then scattered showers 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 70 percent.

Kona

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

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows 69 to 75 near the shore to around 55 near 5000 feet. Light winds. Chance of rain 20 percent.

Independence Day: 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 40 percent.

Waimea

Today: Mostly cloudy. Breezy. Scattered showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 81 near the shore to 69 to 79 near 3000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows around 68 near the shore to 56 to 62 near 3000 feet. East winds 10 to 30 mph. Chance of rain 50 percent.

Independence Day: Windy. Partly sunny with scattered showers. Highs around 81 near the shore to 68 to 78 near 3000 feet. East winds 10 to 30 mph. Chance of rain 50 percent.

Kohala

Today: Mostly cloudy. Breezy. Scattered showers in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 81 near the shore to 69 to 79 near 3000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Tonight: Windy. Mostly cloudy with scattered showers. Lows around 68 near the shore to 56 to 62 near 3000 feet. East winds 10 to 30 mph. Chance of rain 50 percent.

Independence Day: Windy. Partly sunny with scattered showers. Highs around 81 near the shore to 68 to 78 near 3000 feet. East winds 10 to 30 mph. Chance of rain 50 percent.

South Big Island

Today: Breezy. Mostly sunny in the morning, then mostly cloudy with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 86 near the shore to around 73 near 5000 feet. East winds up to 25 mph increasing to 10 to 25 mph in the afternoon. Chance of rain 50 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows around 70 near the shore to around 53 near 5000 feet. East winds 10 to 25 mph shifting to the northeast up to 25 mph after midnight. Chance of rain 20 percent.

Independence Day: 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 up to 30 mph. Chance of rain 20 percent.

Puna

Today: Mostly cloudy. Showers likely in the morning, then showers likely and slight chance of thunderstorms in the afternoon. Highs around 83 near the shore to 69 to 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Mostly cloudy with showers likely. Lows around 68 near the shore to around 54 at 4000 feet. North winds up to 15 mph. Chance of rain 70 percent.

Independence Day: Partly sunny. Breezy. Showers likely in the morning, then scattered showers 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 70 percent.

Waikoloa

Today: Breezy. Mostly sunny in the morning, then partly sunny with scattered showers and slight chance of thunderstorms in the afternoon. Highs around 86 near the shore to 70 to 76 above 4000 feet. Northeast winds up to 25 mph. Chance of rain 50 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows 70 to 75 near the shore to 51 to 58 above 4000 feet. East winds up to 25 mph. Chance of rain 20 percent.

Independence Day: Mostly sunny. Windy. 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.

Detailed Forecast

Synopsis

High pressure north of the state will keep breezy conditions in place through the rest of the 4th of July Holiday weekend. An upper level trough will pass over the islands today, bringing an uptick in windward showers to the island chain and sending a few more showers into leeward communities. A more typical trade wind weather pattern is then expected tonight through Saturday, with a gradual easing of the trades Tuesday through Friday, with a potential rebound in the trades next weekend.

Discussion

Currently at the surface, a 1034 mb high is centered around 1200 miles north of Honolulu, and is driving breezy trades across the island chain early this morning. Infrared satellite imagery shows a band of low clouds moving through the central islands, resulting in mostly cloudy conditions from Oahu to Maui. Meanwhile, variably cloudy skies prevail over windward sections of Kauai and the Big Island, with partly cloudy conditions in the leeward sections of these isles. Radar imagery shows scattered to numerous showers moving through Oahu and Maui County, with scattered windward showers over Kauai and the Big Island. Main short term focus continues to revolve around trade wind trends and rain chances.
High pressure north of the islands will keep breezy conditions in place through Independence Day, with only minor fluctuations in strength. Winds have dropped below advisory levels overnight, and little change in strength is expected during the next couple days. Therefore the Wind Advisory has been cancelled. A couple fronts will slide southward well to the north of the islands through the first half of the week, eroding the eastern periphery of the high and weakening the gradient over the islands. This should result in an easing of the trades beginning Tuesday, with a more noticeable easing expected Wednesday through Friday with moderate trades prevailing. The trades could pick back up to breezy levels next weekend as high pressure strengthens northwest of the island chain.
As for the remaining weather details, a trough aloft will dampen out as it lifts northwestward through the islands today, but as it does, it will drag some deeper moisture through the islands and elevate inversion heights. As a result, we should see a fairly shower morning for windward areas across the state, with showers also reaching leeward communities at times. Conditions should then begin to improve during the afternoon hours, although scattered showers will continue to affect the islands. Additionally, it still appears that conditions could destabilize enough to allow for a thunderstorm or two to develop over the Big Island this afternoon.
Weak troughing aloft is forecast to linger over the islands tonight into next weekend, but drier boundary layer conditions will overspread the state during this time. This should bring a return of more typical, but slightly drier than normal, summertime trade wind conditions. Passing light showers will favor windward and mauka areas, particularly at night and during the early morning hours, with a stray shower reaching leeward areas from time to time. Some deeper moisture may try to work in from the east next weekend, potentially bringing an increase in trade wind showers.

Aviation

A strong area of high pressure anchored north of the islands will continue to generate breezy trades through the TAF period, focusing showers and lower clouds across mainly windward and mauka slopes through tonight. Additionally, sea breeze clouds are expected across sheltered leeward sections of mainly the Big Island again this afternoon, before diminishing late tonight during the transition to land breeze. Mainly VFR cigs and vsby are expected to continue across leeward zones today, while conditions continue to deteriorate toward MVRF across windward slopes as showers and lower clouds continue to expand in areal coverage through this morning.
AIRMET Sierra continues for mountain obscuration across most windward zones due to clouds and showers this morning. Additionally, AIRMET Tango remains in effect through today as the breezy trades continue low level mechanical turbulence leeward of mountains.

Marine

A strong high pressure system far north of the Hawaiian Islands will keep fresh to locally strong trade winds blowing across the region through Wednesday. Trade wind speeds will decrease into the moderate to fresh range by Thursday. A Small Craft Advisory (SCA) continues for all coastal waters through Monday afternoon. SCA winds will likely scale back to the typically windier waters around Maui County and the Big Island by Monday night.
No significant swells are expected for all shores into next week. The strong trades will support rough and choppy surf along east facing shores. The current small south swell will continue to lower today and Monday. The next small long period south swell will arrive on Wednesday and then slowly fade into Friday. The forerunners of another small long period south swell will arrive by next Saturday.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Monday for all Hawaiian waters,

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Data Courtesy of NOAA.gov