Hilo

Today: Mostly cloudy. Scattered showers in the morning, then showers in the afternoon. Locally heavy rainfall possible in the afternoon. Highs 79 to 85 near the shore to 65 to 71 at 4000 feet. Southeast winds up to 10 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 90 percent.

Tonight: Cloudy. Showers in the evening, then showers likely after midnight. Locally heavy rainfall possible in the evening. Lows 65 to 73 near the shore to 56 to 61 at 4000 feet. South winds up to 10 mph. Chance of rain 90 percent.

Thursday: Cloudy with showers likely. Highs 79 to 85 near the shore to 65 to 71 at 4000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Kona

Today: Mostly sunny in the morning, then mostly cloudy with 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.

Tonight: Mostly cloudy with isolated showers. Lows 71 to 76 near the shore to 52 to 58 near 5000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly cloudy. Isolated showers in the morning, then scattered showers in the afternoon. Highs 84 to 89 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 40 percent.

Waimea

Today: Mostly cloudy. Scattered showers in the morning, then showers likely in the afternoon. Highs 66 to 85. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Cloudy. Showers likely in the evening, then scattered showers after midnight. Lows 65 to 72 near the shore to 59 to 65 near 3000 feet. Southeast winds up to 15 mph. Chance of rain 70 percent.

Thursday: Breezy. Cloudy with showers likely. Highs 66 to 85. East winds 10 to 20 mph. Chance of rain 70 percent.

Kohala

Today: Mostly cloudy. Scattered showers in the morning, then showers likely in the afternoon. Highs 66 to 85. Northeast winds up to 15 mph. Chance of rain 70 percent.

Tonight: Cloudy. Showers likely in the evening, then scattered showers after midnight. Lows 65 to 72 near the shore to 59 to 65 near 3000 feet. Southeast winds up to 15 mph. Chance of rain 70 percent.

Thursday: Breezy. Cloudy with showers likely. Highs 66 to 85. East winds 10 to 20 mph. Chance of rain 70 percent.

South Big Island

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

Tonight: Mostly cloudy. Breezy. Scattered showers in the evening. Lows around 74 near the shore to around 55 near 5000 feet. Northeast winds 10 to 20 mph. Chance of rain 40 percent.

Thursday: Mostly cloudy. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 85 near the shore to around 68 near 5000 feet. East winds 10 to 20 mph. Chance of rain 40 percent.

Puna

Today: Mostly cloudy. Scattered showers in the morning, then showers in the afternoon. Locally heavy rainfall possible in the afternoon. Highs 79 to 85 near the shore to 65 to 71 at 4000 feet. Southeast winds up to 10 mph increasing to 10 to 15 mph in the afternoon. Chance of rain 90 percent.

Tonight: Cloudy. Showers in the evening, then showers likely after midnight. Locally heavy rainfall possible in the evening. Lows 65 to 73 near the shore to 56 to 61 at 4000 feet. South winds up to 10 mph. Chance of rain 90 percent.

Thursday: Cloudy with showers likely. Highs 79 to 85 near the shore to 65 to 71 at 4000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 85 to 90 near the shore to 67 to 73 above 4000 feet. Northwest winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy. Isolated showers in the evening. Lows around 75 near the shore to 52 to 57 above 4000 feet. Light winds. Chance of rain 20 percent.

Thursday: Mostly cloudy. Isolated showers in the afternoon. Highs 84 to 90 near the shore to 68 to 74 above 4000 feet. North winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

A trough north of the state will weaken winds into the light to moderate range today. Sea breezes will develop which could trigger increased showers during the afternoon and evening hours. Moisture moving in from the southeast will produce more showers, primarily for windward Big Island areas tonight. Trade winds will increase Thursday, with conditions expected to dry out through the day. Expect a trade wind weather pattern afterwards through the forecast period.

Discussion

An upper low far north moved southwest overnight and lies a few hundred miles north of Oahu this morning. Surface troughing associated with this upper low will pass just north of the state on today, causing local winds to ease and veer toward the east- southeast. Localized sea breezes will lead to scattered showers across the state. Some of these showers may be briefly heavy in the afternoon due to instability associated with the nearby upper low.
Increased moisture is expected to move in from the southeast this afternoon and tonight, fueling briefly heavy showers across east and southeast facing areas of the Big Island and Maui. The rest of the island chain will be shadowed from the Big Island, but scattered showers, some briefly heavy, may occur.
Thursday will be a transition day as the trough begins to move away from the state and high pressure builds to the north. Showery conditions are still expected as breezy trades fill back in from the east. Lingering moisture and instability are expected over the western end of the state, which could lead to brief heavy rainfall over Kauai on Thursday. By Friday, strong trade winds will return across the state with drier conditions. A trade wind weather pattern is then expected to continue through the rest of the forecast period.

Aviation

An upper level low passing just north of the Hawaiian Islands will enhance showers and clouds across the region into Thursday. Light to moderate trade winds will push these clouds across each island favoring the windward and mountain areas. Brief periods of MVFR conditions are possible favoring the overnight to early morning hours.
AIRMETs for Mountain Obscuration remains in effect for north and east sections from Kauai through the Big Island.

Marine

A trough of low pressure will pass by to the north of the state today and tonight, easing the trades across the marine area. The trades will ramp back up to locally strong levels Thursday through the weekend, as the trough exits and a new high builds north of the island chain. Winds will likely reach Small Craft Advisory (SCA) thresholds over the typically windy waters around Maui and Big Island on Thursday, with SCAs expected to expand to most if not all waters Friday and Saturday. The trades should then ease slightly Sunday through early next week as the high to the distant north weakens.
A series of long period south and southwest swells will keep surf along south facing shores near to slightly above the September average through Thursday, before gradually lowering Friday through early next week. Small surf will prevail along north facing shores through the remainder of the work week, with a small bump from a northwest swell expected this weekend. Another small but slightly larger northwest swell is possible Tuesday and Wednesday of next week. East shore surf will remain well below normal today, rise to near seasonal levels Thursday through Saturday as trade winds ramp up over and upstream of the islands, then lower a notch Sunday into early next week as the trade winds ease.

HFO Watches/Warnings/Advisories

None.

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