Hilo

Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 81 to 87 near the shore to 66 to 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 72 near the shore to around 58 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 50 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 80 to 86 near the shore to 64 to 74 at 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Kona

Today: Sunny. Isolated showers in the afternoon. Highs 85 to 90 near the shore to around 72 near 5000 feet. Light winds. Chance of rain 20 percent.

Tonight: Clear. Lows around 74 near the shore to 50 to 56 near 5000 feet. Light winds.

Monday: Sunny in the morning, then partly sunny with 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 sunny. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 82 near the shore to 71 to 81 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 72 near the shore to 56 to 64 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Monday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 81 near the shore to 70 to 80 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Kohala

Today: Mostly sunny. Breezy. Isolated showers in the morning, then scattered showers in the afternoon. Highs around 82 near the shore to 71 to 81 near 3000 feet. East winds 10 to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 72 near the shore to 56 to 64 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Monday: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 81 near the shore to 70 to 80 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Sunny and breezy. Highs around 87 near the shore to around 69 near 5000 feet. East winds up to 20 mph.

Tonight: Clear. Lows around 75 near the shore to around 53 near 5000 feet. Northeast winds up to 15 mph.

Monday: Sunny. Isolated showers in the afternoon. Highs around 85 near the shore to around 66 near 5000 feet. East winds up to 15 mph. Chance of rain 20 percent.

Puna

Today: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 81 to 87 near the shore to 66 to 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 72 near the shore to around 58 at 4000 feet. Northwest winds up to 15 mph. Chance of rain 50 percent.

Monday: Mostly sunny in the morning then becoming partly sunny. Scattered showers. Highs 80 to 86 near the shore to 64 to 74 at 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Waikoloa

Today: Sunny. Highs 85 to 91 near the shore to 67 to 76 above 4000 feet. Northeast winds up to 15 mph.

Tonight: Clear. Lows around 76 near the shore to 53 to 58 above 4000 feet. Southeast winds up to 15 mph.

Monday: Sunny. Highs 85 to 90 near the shore to 66 to 74 above 4000 feet. Northwest winds up to 10 mph.

Detailed Forecast

Synopsis

Moderate to locally breezy trade winds will deliver passing clouds and showers through today, mainly to windward and mauka areas. Winds will become light Monday through the week, with overall drier conditions and limited showers over interior areas during each afternoon.

Discussion

A high pressure ridge north and northeast of Hawaii will continue to drive breezy trades today. A fairly typical and relatively benign trade wind weather pattern remains in place today. This morning sounding looks relatively more stable than the sounding yesterday, and precipitable water measurements have also declined slightly more towards normal. Satellite imagery show isolated thunderstorms have stayed just northwest of the coastal water region overnight. Radar imagery show clouds and scattered showers embedded in the tradewind flow and focusing along windward and mauka areas with dry and mostly clear conditions along leeward areas.
Trade wind speeds will slowly diminish today and tonight as a surface low pressure system to the distant northwest moves east and weakens the ridge. A weakening front associated with the low will draw closer to the islands and the surface ridge will move over the islands. A mid- level ridge will also build over the area from the west starting Monday, further contributing to a mostly dry, light wind pattern through the first half of next week. Some interior and upslope clouds may develop in response to daytime heating, but little in the way of rainfall is expected, with mostly clear nights and mornings.
Depending on the evolution of the parent low north of the islands, the weakening front may move over the western portion of the state during the second half of the week. However, there is still considerable differences with timing with model guidance. Either way, the recent persistent trade wind flow will have an extended absence.

Aviation

Moderate to breezy trade winds will gradually trend weaker later today, but should stay predominate with land/sea breezes not expected until Monday or Tuesday. Clouds and showers will primarily focus on the windward and mountain areas, with the greatest coverage and intensity during the overnight through early morning hours. Brief periods of MVFR ceilings and visibility will be possible with any of the heavier showers.
AIRMET Tango remains in effect for tempo moderate turbulence below 9000 feet for areas downwind (south through west) of island terrain. This AIRMET will likely remain in effect through mid day and then conditions should begin to improve during the afternoon or evening hours.

Marine

A high far north-northeast of the main Hawaiian Islands will continue to drive moderate to locally strong trades across coastal waters through today. The Small Craft Advisory (SCA) for the typical windier waters near Maui County and the Big Island has been extended through tonight. By Monday, a low far to the northwest will push the ridge south, causing winds to weaken. Weaker winds will persist through much of the new week. An upper low continues to generate thunderstorms over the northern offshore waters which may recur over the next several days.
A medium period northwest swell is expected to arrive today, peak tonight and Monday, then slowly subside Tuesday. A slightly larger northwest medium period swell will arrive late Tuesday, then persist through Thursday. Trade winds near and upstream of the islands will continue to bring short period, choppy surf to east facing shores through today, but expect this to drop off Monday as winds weaken. A series of background southerly swells will continue over the next several days. A small long period south swell will arrive Monday night and linger into Thursday. Another small long period south swell will arrive Friday. A slightly larger medium period southeast swell arriving at the same time as the first long period south swell will help boost surf along south facing shores.

HFO Watches/Warnings/Advisories

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

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Data Courtesy of NOAA.gov