Hilo

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 77 to 87 near the shore to around 71 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 72 near the shore to 56 to 61 at 4000 feet. West winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs 78 to 88 near the shore to around 71 at 4000 feet. Southeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain 50 percent.

Kona

Today: Mostly sunny in the morning then becoming partly sunny. Isolated showers. Highs 82 to 88 near the shore to around 68 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Isolated showers in the evening. Lows around 75 near the shore to 51 to 56 near 5000 feet. Light winds. Chance of rain 20 percent.

Friday: Mostly sunny. Isolated showers in the afternoon. Highs 84 to 89 near the shore to around 70 near 5000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Waimea

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 73 to 81 near the shore to 67 to 80 near 3000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 65 to 72 near the shore to 58 to 63 near 3000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Friday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 75 to 82 near the shore to 69 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Kohala

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 73 to 81 near the shore to 67 to 80 near 3000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then partly cloudy with isolated showers after midnight. Lows 65 to 72 near the shore to 58 to 63 near 3000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Friday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs 75 to 82 near the shore to 69 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Mostly sunny. Isolated showers in the afternoon. Highs around 86 near the shore to around 68 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Tonight: Mostly clear. Lows around 73 near the shore to around 52 near 5000 feet. Northeast winds up to 15 mph.

Friday: Mostly sunny. Breezy. Highs around 87 near the shore to around 69 near 5000 feet. East winds up to 20 mph.

Puna

Today: Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 77 to 87 near the shore to around 71 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 66 to 72 near the shore to 56 to 61 at 4000 feet. West winds up to 10 mph. Chance of rain 50 percent.

Friday: Partly sunny with scattered showers. Highs 78 to 88 near the shore to around 71 at 4000 feet. Southeast winds up to 15 mph shifting to the east in the afternoon. Chance of rain 50 percent.

Waikoloa

Today: Mostly sunny. Isolated showers in the afternoon. Highs around 86 near the shore to 65 to 73 above 4000 feet. West winds up to 10 mph. Chance of rain 20 percent.

Tonight: Partly cloudy. Lows around 76 near the shore to 53 to 58 above 4000 feet. Light winds.

Friday: Mostly sunny. Highs 84 to 89 near the shore to 67 to 75 above 4000 feet. West winds up to 10 mph.

Detailed Forecast

Synopsis

Gentle to moderate trade winds will trend weaker through Friday, then gradually strengthen through the weekend to become moderate to breezy by early next week. Limited low clouds and showers will favor windward and mauka areas with the exceptions being on Friday when winds become light enough to allow for sea breeze development and Friday night into Saturday as a plume of slightly enhanced moisture moves through the state.

Discussion

A low pressure system is situated about 1100 miles northeast of the state as of this morning. This low is weakening the ridge that is extending across the Eastern and Central Pacific, which in turn is reducing the pressure gradient across the state. Gentle to moderate trade winds will become light to gentle by Friday as the low pressure system broadens to our north. With a fairly dry and stable airmass over the state, limited clouds and showers will remain concentrated over windward and mauka areas into early next week. Some showers may spill over to leeward areas during the overnight night hours. Chances of clouds and showers may increase slightly over leeward interior areas Friday afternoon as light winds support sea breeze development. For Kona slopes of the Big Island, clouds will increase in coverage during the daytime hours as sea breezes develop and then clear/push offshore overnight as land breezes kick in.
Global models show a subtle plume of enhanced moisture moving across the state Friday night through Saturday, a slight uptick in low clouds and showers to windward and mauka areas is expected through that period. Dewpoint temperatures will also creep up in the low 70's making air temperatures feel slightly warmer over the weekend and linger into next week.
Moderate to locally breezy trade winds will then gradually return over the weekend into early next week as the low lifts further northeastward, allowing the ridge to strengthen northeast of the state.

Aviation

A mostly dry and stable airmass over the islands will limit cloud and shower development, with moderate trade winds continuing through the rest of week. VFR conditions expected to prevail.
No AIRMETs are in effect, and none are expected today.

Marine

Trade winds will gradually ease through Friday as a broad area of low pressure deepens far northeast of the state. Wind speeds will restrengthen to moderate to locally strong levels over the weekend as the ridge to the north builds back over the islands.
A moderate south swell will continue to build through the day, peaking Friday night, then slowly decline over the weekend. Surf heights at the peak of the swell should remain just below High Surf Advisory criteria.
Surf along east facing shores will slowly decline by the end of the week as trade winds decline. Surf along north facing shores will remain tiny through the end of the week. In the long range, a small out of season north- northwest swell is possible around Monday of next week.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov