Hilo

Today: Partly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 66 to 71 near the shore to around 56 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 85 near the shore to 68 to 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Kona

Today: Mostly sunny with isolated showers in the morning, then mostly cloudy with numerous showers in the afternoon. Highs 83 to 89 near the shore to around 70 near 5000 feet. Light winds. Chance of rain 60 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then mostly clear after midnight. Lows 70 to 75 near the shore to around 55 near 5000 feet. Light winds. Chance of rain 40 percent.

Monday: Sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs 83 to 89 near the shore to around 70 near 5000 feet. West winds up to 10 mph. Chance of rain 40 percent.

Waimea

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 83 near the shore to 73 to 82 near 3000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 70 near the shore to 56 to 63 near 3000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Monday: Partly sunny with scattered showers. Highs around 82 near the shore to 72 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

Kohala

Today: Mostly sunny with isolated showers in the morning, then partly sunny with scattered showers in the afternoon. Highs around 83 near the shore to 73 to 82 near 3000 feet. East winds up to 15 mph. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 70 near the shore to 56 to 63 near 3000 feet. East winds 10 to 15 mph decreasing to up to 15 mph after midnight. Chance of rain 50 percent.

Monday: Partly sunny with scattered showers. Highs around 82 near the shore to 72 to 81 near 3000 feet. East winds up to 15 mph. Chance of rain 50 percent.

South Big Island

Today: Breezy. Mostly sunny with isolated showers in the morning, then mostly cloudy with scattered showers in the afternoon. Highs around 87 near the shore to around 72 near 5000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then clear after midnight. Lows around 72 near the shore to around 53 near 5000 feet. Northeast winds up to 15 mph. Chance of rain 40 percent.

Monday: Breezy. Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 86 near the shore to around 72 near 5000 feet. East winds up to 20 mph. Chance of rain 20 percent.

Puna

Today: Partly sunny with scattered showers. Highs around 86 near the shore to 70 to 75 at 4000 feet. East winds up to 10 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy. Scattered showers in the evening, then numerous showers after midnight. Lows 66 to 71 near the shore to around 56 at 4000 feet. Northwest winds up to 10 mph. Chance of rain 70 percent.

Monday: Mostly cloudy. Numerous showers in the morning, then scattered showers in the afternoon. Highs around 85 near the shore to 68 to 74 at 4000 feet. Northeast winds up to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Sunny in the morning, then mostly cloudy with scattered showers in the afternoon. Highs around 88 near the shore to 70 to 76 above 4000 feet. North winds up to 15 mph. Chance of rain 50 percent.

Tonight: Mostly cloudy with scattered showers in the evening, then clear after midnight. Lows around 73 near the shore to 52 to 58 above 4000 feet. East winds up to 15 mph. Chance of rain 30 percent.

Monday: Sunny in the morning then becoming partly sunny. Highs around 87 near the shore to 70 to 75 above 4000 feet. North winds up to 15 mph.

Detailed Forecast

Synopsis

The hybrid light trade wind and sea breeze weather pattern will continue for one more day today. Clouds and slow moving showers will favor mountain and island interior sections each afternoon to early evening, then shift towards windward areas in the overnight hours. The weather pattern changes on Monday as the high pressure ridge strengthens north of the region. Trade winds will trend back to moderate levels by Tuesday, with passing clouds and showers favoring windward and mountain areas lasting into next weekend.

Discussion

Numerous unstable showers continue to develop in the coastal waters this morning as shown on local radar imagery. An upper level trough shown on satellite water vapor imagery near Kauai continues to sweep eastward through the region today. This trough will keep temperature inversion heights in the 7,000 to 10,000 foot range allowing deeper cumulus cloud development and yet another day of afternoon to early evening mountain and island interior section sea breeze showers across the state. Slow moving moderate to locally heavy showers may increase the potential for water ponding on area roadways and higher stream levels in the afternoon to early evening hours. Overnight cloud and shower coverage will favor windward areas.
The ridge will slowly build north of the state on Monday and Tuesday as we transition back to more moderate trade winds. Sea breezes will become more localized and confined mainly to the terrain sheltered western slopes of each island. Clouds and showers will trend back to the more typical windward and mountain areas from Tuesday into next weekend, favoring overnight to early morning hours. A small increase in shower activity will favor windward sections of Maui and the Big Island from Monday night through Wednesday as a band of moisture drifts into these southeastern islands on the trade winds. Isolated thunderstorms may form over the mountain slopes of the Big Island on Tuesday afternoon. Kauai may also see a slight boost to rainfall potential as the upper low northwest of the state lingers closer to the Garden Isle. Elsewhere more typical trade wind weather will prevail into next weekend.

Aviation

Light trade winds along with an area of enhanced moisture and an upper trough in the area will support clouds and spotty showers over windward and mauka locations. Expect some showers to impact leeward and interior locations through the afternoon hours where sea breezes form today.
No AIRMETs are in effect at this time.

Marine

With weak high pressure persisting far north of the islands, trade winds will remain light to moderate through the weekend. Winds will strengthen modestly early in the new work week, becoming moderate to fresh.
The incoming south-southwest swell will increase surf along south-facing shores, peaking near the High Surf Advisory height of 10 feet by late today into Monday, then slowly fading through midweek. A medium-period southeast swell arriving Monday will be added to the mix and will hang on through Wednesday. Surf along east-facing shores will ease as trades back off, but may come up to some extent today if a medium-period easterly swell from former Hurricane Kay reaches our shores. Choppy wind waves along east shores will pick up in the new week in response to strengthening trades.

HFO Watches/Warnings/Advisories

None.

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Data Courtesy of NOAA.gov