Hilo

Today: Breezy. Mostly sunny with scattered showers in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 78 to 83 near the shore to 63 to 72 at 4000 feet. North winds 10 to 20 mph shifting to the east up to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Cloudy and breezy. Numerous showers in the evening, then showers after midnight. Lows 64 to 72 near the shore to 54 to 59 at 4000 feet. East winds up to 15 mph shifting to the west after midnight. Chance of rain 80 percent.

Thursday: Breezy. Cloudy with numerous showers. Highs 80 to 85 near the shore to 65 to 73 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Kona

Today: Mostly sunny in the morning then becoming cloudy. Isolated showers. Highs around 85 near the shore to around 67 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy after midnight. Lows 70 to 75 near the shore to 51 to 56 near 5000 feet. Light winds. Chance of rain 40 percent.

Thursday: Mostly sunny in the morning, then cloudy with scattered showers in the afternoon. Highs around 86 near the shore to around 69 near 5000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Waimea

Today: Mostly sunny in the morning then becoming mostly cloudy. Windy. Isolated showers. Highs 65 to 87. East winds up to 30 mph increasing to 10 to 30 mph in the afternoon. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 63 to 70 near the shore to 55 to 62 near 3000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Thursday: Partly sunny in the morning then becoming cloudy. Windy. Scattered showers. Highs 66 to 88. East winds up to 25 mph increasing to 10 to 30 mph in the afternoon. Chance of rain 50 percent.

Kohala

Today: Mostly sunny in the morning then becoming mostly cloudy. Windy. Isolated showers. Highs 65 to 87. East winds up to 30 mph increasing to 10 to 30 mph in the afternoon. Chance of rain 20 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 63 to 70 near the shore to 55 to 62 near 3000 feet. East winds up to 25 mph. Chance of rain 50 percent.

Thursday: Partly sunny in the morning then becoming cloudy. Windy. Scattered showers. Highs 66 to 88. East winds up to 25 mph increasing to 10 to 30 mph in the afternoon. Chance of rain 50 percent.

South Big Island

Today: Sunny in the morning then becoming mostly cloudy. Breezy. Highs around 83 near the shore to around 67 near 5000 feet. East winds 10 to 25 mph.

Tonight: Breezy. Mostly cloudy with isolated showers in the evening, then mostly clear after midnight. Lows around 72 near the shore to around 52 near 5000 feet. East winds 10 to 25 mph shifting to the northeast up to 25 mph after midnight. Chance of rain 20 percent.

Thursday: Breezy. Sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs around 85 near the shore to around 68 near 5000 feet. East winds up to 25 mph. Chance of rain 30 percent.

Puna

Today: Breezy. Mostly sunny with scattered showers in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 78 to 83 near the shore to 63 to 72 at 4000 feet. North winds 10 to 20 mph shifting to the east up to 20 mph in the afternoon. Chance of rain 50 percent.

Tonight: Cloudy and breezy. Numerous showers in the evening, then showers after midnight. Lows 64 to 72 near the shore to 54 to 59 at 4000 feet. East winds up to 15 mph shifting to the west after midnight. Chance of rain 80 percent.

Thursday: Breezy. Cloudy with numerous showers. Highs 80 to 85 near the shore to 65 to 73 at 4000 feet. Northeast winds up to 15 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 70 percent.

Waikoloa

Today: Sunny in the morning then becoming partly sunny. Breezy. Highs 80 to 88 near the shore to 65 to 72 above 4000 feet. Northeast winds up to 20 mph.

Tonight: Mostly cloudy with isolated showers in the evening, then mostly clear after midnight. Lows around 73 near the shore to 50 to 56 above 4000 feet. Southeast winds up to 10 mph. Chance of rain 20 percent.

Thursday: Breezy. Sunny in the morning, then mostly cloudy with isolated showers in the afternoon. Highs 81 to 90 near the shore to 66 to 73 above 4000 feet. Northeast winds up to 15 mph increasing to up to 25 mph in the afternoon. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A high pressure system far north of the Hawaiian islands will keep moderate to breezy trade winds blowing across the state into the first half of next week. Passing clouds and showers will drift through windward and mountain areas, favoring the overnight to early morning hours. An upper level disturbance may briefly increase cloud and shower coverage this weekend. More stable weather trends continue from Monday into the first half of next week.

Discussion

The satellite picture this evening looks fairly stable just upstream of the Hawaiian Islands with just a few bands of clouds drifting in on the trade winds. A larger band of more organized clouds is setting up east of the Big Island near 150W longitude that may bring a brief increase in clouds and showers to the windward Big Island and Maui by Wednesday night. High level cirrus clouds aloft, associated with a weak subtropical jet stream, have diminished in coverage and drifted just north of the island chain. Local Hawaiian radar imagery shows isolated to scattered light showers riding in on the trade winds.
A high pressure system roughly 1,400 miles north to northeast of the state will continue to produce moderate to breezy trade winds across the region into the middle of next week. Typical trade wind weather conditions remain in the forecast through Friday with brief passing showers over windward and mountain sections, favoring the overnight to early morning hours. Isolated showers are possible over leeward areas mainly during the overnight hours. The Big Island will see typical sea breezes along the Kona side of the island with clouds building each day and isolated to scattered shower coverage. Evening clouds and showers over the leeward Big Island will trend lower around midnight as the more stable mountain breezes push the moisture offshore.
The weather pattern gets more complex this weekend as a small cold core upper low drifts from southeast to northwest across the island chain. This unstable disturbance will reach the Big Island on Saturday, Maui County by Saturday night, and then drift over Oahu and Kauai from Sunday to Sunday night. This system may enhance cloud cover and shower activity as it passes through each island, especially in the overnight to early morning hours. This translates to a slight boost in rainfall coverage for the Big Island and Maui County by Saturday night and slightly higher rainfall trends for Oahu and Kauai by Sunday night.
The upper low drifts northwestward away from the islands by Monday. A building upper level ridge will bring drier and more stable weather trends lasting into the middle of next week.

Aviation

Moderate to breezy trade winds will continue. AIRMET Tango for low-level mechanical turbulence to the lee of higher terrain terrain will remain necessary through at least Wednesday evening.
Bands of low topped clouds and light trade wind shower will affect mainly north and east facing slopes coasts. Isolated spillover showers are to be expected across leeward areas especially in the late night and morning hours. MVFR CIG and VIS probable in passing showers, otherwise VFR conditions will prevail all areas.
Regarding Leeward Big Island, a weak eddy remains anchored just west of the island and is promoting weak onshore flow along the Kona Coast. VFR cloudiness is likely to persist between Kona- Kailua and South Point through midday Thursday and possibly beyond.

Marine

Fresh to strong easterly trade winds have returned and are here to stay through the upcoming weekend as the ridge strengthens to the north. Trades may become strong over most waters Friday through the weekend as 1030-1035 mb high sets up due north of the islands. Seas will respond and become rough, potentially reaching the 10 ft Small Craft level over the waters south of the Big Island and in the Alenuihaha Channel this weekend.
Surf along south facing shores will hold near the advisory level into Wednesday, then ease through the second half of the week as the reinforcing shot of south swell moves through. Buoy observations south of the islands are reflecting quite the gradient this evening with a 5 ft swell height (12-16 second band) reading at 51004 (southeast of the Big Island) and 2-3 ft within the same frequency band at buoy 51002 directory to the south.
Surf along east facing shores will steadily trend up through the week as the local and upstream trades increase. This should result in rough conditions for easterly exposures by and through the weekend. Confidence remains low for any long-period pulse locally associated with former Tropical Cyclone Celia in the far eastern Pacific.
Surf along north facing shores will remain at seasonal levels (near flat) through the weekend.

HFO Watches/Warnings/Advisories

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

Big Island Now Weather is brought to you by Blue Hawaiian Helicopters.

Check out their Big Island Helicopter Tours today!

Data Courtesy of NOAA.gov