Photo Credit: James Grenz

Hilo

Today: Mostly cloudy with scattered showers. Highs 78 to 83 near the shore to 61 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with numerous showers. Lows 63 to 72 near the shore to around 56 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Thursday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 77 to 83 near the shore to 62 to 71 at 4000 feet. North winds up to 15 mph. Chance of rain 70 percent.

Kona

Today: Mostly sunny in the morning, then partly sunny with scattered showers in the afternoon. Highs around 85 near the shore to around 68 near 5000 feet. Light winds. Chance of rain 40 percent.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Isolated showers. Lows around 72 near the shore to around 56 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly sunny. Isolated showers in the afternoon. Highs around 86 near the shore to around 68 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Waimea

Today: Breezy. Partly sunny with scattered showers. Highs 65 to 87. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 63 to 69 near the shore to 55 to 63 near 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers. Highs 65 to 87. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

Kohala

Today: Breezy. Partly sunny with scattered showers. Highs 65 to 87. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 63 to 69 near the shore to 55 to 63 near 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Thursday: Breezy. Partly sunny with scattered showers. Highs 65 to 87. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 50 percent.

South Big Island

Today: Breezy. Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 84 near the shore to around 67 near 5000 feet. East winds up 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 73 near the shore to around 53 near 5000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Thursday: Mostly sunny. Breezy. Isolated showers in the afternoon. Highs around 86 near the shore to around 68 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Puna

Today: Mostly cloudy with scattered showers. Highs 78 to 83 near the shore to 61 to 70 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with numerous showers. Lows 63 to 72 near the shore to around 56 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Thursday: Partly sunny. Numerous showers in the morning, then scattered showers in the afternoon. Highs 77 to 83 near the shore to 62 to 71 at 4000 feet. North winds up to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Breezy. Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 81 to 89 near the shore to 66 to 72 above 4000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Breezy. Isolated showers in the evening. Lows around 72 near the shore to 51 to 57 above 4000 feet. Southeast winds up to 20 mph. Chance of rain 20 percent.

Thursday: Mostly sunny. Breezy. Highs 82 to 89 near the shore to 68 to 73 above 4000 feet. Northeast winds up to 20 mph.

Detailed Forecast

Synopsis

High pressure far to the north to northwest of the islands will drive trade winds through the next week. Bands of moisture may affect windward portions of Kauai and the Big Island beginning late tonight through Saturday.

Discussion

High pressure far to the north to northwest of the islands will drive trade winds through the next week. A weakness in the high from a surface trough will track southward and decrease the wind speeds slightly tonight into Friday. An upper level trough to the northwest of the islands is helping to bring some high clouds over the islands from time to time through the rest of the week. Otherwise, expect mostly dry and stable weather statewide today.
GFS and ECMWF show two bands of moisture moving in almost simultaneously beginning late tonight into Saturday. One band is forecast to slowly move in from the north and stall over Kauai, while a second area tracks in along a weak surface trough and grazes the Big Island (while the brunt of the moisture passes by to the south). Windward and mauka areas of these islands would likely see most of the rainfall associated with the bands. The moisture should clear the islands by Sunday.
The aforementioned trough north of Hawaii will wash out and carry westward by the trade winds by Friday. Meanwhile the high to the north and northwest will slide eastward resulting in a slight strengthening of the trade winds this weekend into early next week.

Aviation

High pressure anchored north of the islands will maintain the locally strong easterly trade winds through the TAF period, with showers and clouds remaining focused mainly across favored windward and mountain locations. Sea breeze clouds and isolated showers will develop again this afternoon across sheltered leeward sections. Mainly VFR conds are expected across TAF sites through tonight. Periodic MVFR cigs will occasionally drift across windward areas today, though are not expected to become widespread and remaining below AIRMET criteria.
AIRMET Tango remains in effect for low-level mechanical turbulence leeward of mountains due to strong trades. These turbulent conditions area expected to continue into tonight, however winds will slowly diminish in intensity across the western islands later this afternoon which could reduce the threat of low-level mechanical turbulence across Kauai.

Marine

Strong high pressure north of the islands will keep moderate to locally strong trades in place through Friday. The trades will then ramp back up to fresh to strong levels over the weekend and into early next week. A Small Craft Advisory (SCA) remains in effect for the windier zones around Maui and the Big Island through 6 PM Friday, and will likely need to be extended in time as the week progresses. The SCA has been cancelled for the Kaiwi Channel.
No significant swells are expected over the next several days. East shore surf will remain slightly below normal through Thursday, before ramping back up to near seasonal levels Friday through early next week as the trades strengthen over and upstream of the island chain. South shore surf will remain small through Saturday, before a long-period south swell arrives and boosts surf to near or slightly above the summertime average Sunday through early next week. East Pacific Hurricane Bonnie may send a small, long-period east swell our way early next week.

HFO Watches/Warnings/Advisories

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

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Data Courtesy of NOAA.gov