Hilo

Tonight: Mostly cloudy with scattered showers. Lows 64 to 72 near the shore to 54 to 59 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 79 to 84 near the shore to 63 to 72 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 70 percent.

Friday Night: Mostly cloudy with scattered showers. Lows 64 to 72 near the shore to around 57 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Kona

Tonight: Mostly cloudy in the evening then becoming mostly clear. Isolated showers. Lows around 73 near the shore to around 56 near 5000 feet. Light winds. Chance of rain 20 percent.

Friday: Sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs around 86 near the shore to around 68 near 5000 feet. Light winds. Chance of rain 40 percent.

Friday Night: Mostly cloudy in the evening then becoming mostly clear. Isolated showers. Lows around 73 near the shore to 53 to 58 near 5000 feet. Light winds. Chance of rain 20 percent.

Waimea

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Scattered showers. Lows 64 to 69 near the shore to 55 to 64 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Friday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 66 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

Friday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 64 to 69 near the shore to 56 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

Kohala

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Breezy. Scattered showers. Lows 64 to 69 near the shore to 55 to 64 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Friday: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 66 to 87. East winds 10 to 15 mph. Chance of rain 50 percent.

Friday Night: Mostly cloudy in the evening then becoming partly cloudy. Scattered showers. Lows 64 to 69 near the shore to 56 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 50 percent.

South Big Island

Tonight: Mostly clear. Breezy. Lows around 73 near the shore to around 53 near 5000 feet. Northeast winds up to 20 mph.

Friday: Sunny. Isolated showers in the afternoon. Highs around 85 near the shore to around 68 near 5000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

Friday Night: Mostly clear. Lows around 73 near the shore to around 54 near 5000 feet. East winds 10 to 15 mph.

Puna

Tonight: Mostly cloudy with scattered showers. Lows 64 to 72 near the shore to 54 to 59 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny. Showers likely in the morning, then scattered showers in the afternoon. Highs 79 to 84 near the shore to 63 to 72 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 70 percent.

Friday Night: Mostly cloudy with scattered showers. Lows 64 to 72 near the shore to around 57 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Waikoloa

Tonight: Mostly clear. Breezy. Lows 70 to 75 near the shore to 51 to 58 above 4000 feet. East winds up to 20 mph.

Friday: Sunny. Isolated showers in the afternoon. Highs 82 to 89 near the shore to 66 to 74 above 4000 feet. Light winds. Chance of rain 20 percent.

Friday Night: Mostly clear. Lows 70 to 75 near the shore to 52 to 58 above 4000 feet. Light winds.

Detailed Forecast

Synopsis

Moderate to locally breezy trade winds will prevail through the week. A typical summertime weather pattern will focus clouds and showers over windward slopes. Aside from afternoon showers over the Kona slopes of the Big Island, leeward areas will be rather dry.

Discussion

Locally breezy trades and a typical summertime rainfall pattern will continue through the week. A persistent mid level ridge will keep stable conditions in place, with an inversion holding around 6,000 to 8,000 ft. As a result, trade winds will focus modest showers over windward slopes. Rainfall at most windward sites will generally be less than a quarter of an inch each day, but pockets of moisture within the trade wind flow will periodically boost rainfall. One such pocket will move in tonight and clear out late Thursday morning. Leeward Big Island will see clouds and spotty showers each afternoon, while leeward areas elsewhere will continue to experience little rainfall accumulation.

Aviation

Breezy to locally strong trade winds continue, with AIRMET Tango for low-level turbulence over and downwind of the terrain of all islands in effect for the foreseeable future.
Clouds and showers have continued to favor windward and mauka areas and have been rather persistent overnight resulting in periods of mountain obscuration. Expect AIRMET Sierra to remain in effect for windward portions of all islands through the morning hours, with conditions improving this afternoon. Otherwise, VFR conditions will prevail across the state.

Marine

High pressure north or the state will keep moderate to locally strong trade winds in place through the forecast period, with only minor fluctuations in strength. A Small Craft Advisory remains in effect for the typically windy waters around Maui and the Big Island through 6 PM this evening.
Only small surf is expected through this weekend along south facing shores. A new small, long-period south swell could give south shore surf a small boost early next week. A much larger long- period south swell is forecast to arrive late next week (Thursday 7/28), potentially pushing south shore surf back up above advisory levels.
Steady trade wind swell will keep east shore surf near to slightly below normal levels during the next 7 days. A small, longer period east swell associated with tropical cyclone Estelle may give surf a small boost over the weekend. North shore surf will remain flat during the next 7 days.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST this evening 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