Hilo

Today: Partly sunny with scattered showers. Highs 80 to 85 near the shore to 65 to 74 at 4000 feet. Northeast winds 10 to 15 mph shifting to the east in the afternoon. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 72 near the shore to around 58 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Monday: Mostly cloudy with showers likely. Highs around 82 near the shore to 65 to 74 at 4000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Kona

Today: Mostly sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs around 87 near the shore to around 70 near 5000 feet. Northwest winds up to 10 mph. Chance of rain 20 percent.

Tonight: Mostly cloudy with isolated showers in the evening, then mostly clear after midnight. Lows around 73 near the shore to 51 to 56 near 5000 feet. Light winds. Chance of rain 20 percent.

Monday: Sunny in the morning, then cloudy with scattered showers in the afternoon. Highs around 88 near the shore to around 72 near 5000 feet. North winds up to 10 mph. Chance of rain 50 percent.

Waimea

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 68 to 88. East winds up to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with scattered showers. Lows around 67 near the shore to 57 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

Monday: Breezy. Mostly cloudy with showers likely. Highs 69 to 88. East winds 10 to 20 mph. Chance of rain 70 percent.

Kohala

Today: Mostly sunny. Scattered showers in the morning, then isolated showers in the afternoon. Highs 68 to 88. East winds up to 15 mph. Chance of rain 30 percent.

Tonight: Partly cloudy with scattered showers. Lows around 67 near the shore to 57 to 64 near 3000 feet. East winds 10 to 15 mph. Chance of rain 40 percent.

Monday: Breezy. Mostly cloudy with showers likely. Highs 69 to 88. East winds 10 to 20 mph. Chance of rain 70 percent.

South Big Island

Today: Mostly sunny. Breezy. Highs around 85 near the shore to around 70 near 5000 feet. East winds up to 20 mph.

Tonight: Mostly clear. Lows around 74 near the shore to around 53 near 5000 feet. Northeast winds 10 to 15 mph.

Monday: Breezy. Sunny with isolated showers in the morning, then cloudy with showers likely in the afternoon. Highs around 87 near the shore to around 70 near 5000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Puna

Today: Partly sunny with scattered showers. Highs 80 to 85 near the shore to 65 to 74 at 4000 feet. Northeast winds 10 to 15 mph shifting to the east in the afternoon. Chance of rain 40 percent.

Tonight: Mostly cloudy with scattered showers. Lows 65 to 72 near the shore to around 58 at 4000 feet. Northeast winds up to 10 mph. Chance of rain 50 percent.

Monday: Mostly cloudy with showers likely. Highs around 82 near the shore to 65 to 74 at 4000 feet. East winds 10 to 15 mph. Chance of rain 70 percent.

Waikoloa

Today: Mostly sunny. Highs 82 to 90 near the shore to 67 to 76 above 4000 feet. North winds up to 15 mph.

Tonight: Mostly clear. Lows 70 to 75 near the shore to 50 to 58 above 4000 feet. Light winds.

Monday: Sunny in the morning, then partly sunny with isolated showers in the afternoon. Highs 82 to 90 near the shore to 68 to 76 above 4000 feet. Northeast winds up to 10 mph. Chance of rain 20 percent.

Detailed Forecast

Synopsis

Trade winds across the southern end of the state will spread over the remaining islands as the day wears on. A drier airmass moving in from the east will produce fair trade wind weather for most areas today. A return of windward and mauka showers are expected Monday with trades gradually strengthening during the first half of next week. Locally strong trades are possibly by middle of next week.

Discussion

As expected no major changes with the morning forecast package. Have nudge PoPs upwards near Kauai and somewhat near Oahu today and this evening. A batch of heavier showers moved over the windward side of Kauai overnight, but was short lived. The possibility of similar shower activity will remain a possibility near Kauai today, but expect improving conditions as the day wears on.
The surface ridge that have been over the islands is lifting to the north, and has allowed trade winds to start filtering back over the southern islands. Expect the trade winds to spread over the remaining islands today, resulting in a hybrid sea breeze/trade wind pattern, with trades expected statewide by Monday, building further during the first half of the new week.
A surface trough to the west of the islands is the driving force behind the showers near Kauai mentioned above. This trough is expected to continue to move to the west and weaken. High clouds streaming over the islands from the west are due to an upper level trough to the north of the islands. This upper level feature is expected to lift northward, which will pull the high clouds with it.
A more typical trade winds shower pattern is expected starting Monday and continuing into midweek as the ridge of high pressure becomes further established far north of the state. Locally strong trades are possible by mid- week as an area of low pressure potentially develops and passes far south of the state.

Aviation

Early Sunday morning radar and satellite imagery reveals a band of showers passing over Kauai and the Kauai Channel. Brief MVFR CIG or VIS in moderate showers is likely in this band. These showers should exit the area by noon, today. Meanwhile, multiple bands of weak showers can be seen just upstream of the Islands and are expected to reach windward Big Island and East Maui by morning.
Easterly trade wind flow has become re-established across the Big Island and Maui: conditions are expected to spread across the remainder of the state by afternoon. Shower activity this afternoon should be limited and impact mainly east facing slopes and coasts.
AIRMET Tango remains in effect for portions of Maui and Molokai due to low-level mechanical turbulence leeward of mountains.

Marine

Easterly trade winds will gradually strengthen from east to west over the next couple of days. A surface trough far northwest of Kauai will slowly weaken and drift northward during this time, allowing high pressure to the distant north to exert a greater influence. The Small Craft Advisory (SCA) has been scaled back to the typically windy waters around Maui County and the Big Island. The SCA has also been extended through early morning Tuesday. A further increase in winds is possible Tuesday and Wednesday as a potential tropical disturbance passes far south of the islands. If this occurs, a SCA could be needed for most Hawaiian waters.
Little significant swell is anticipated through next week. A small short-period northeast swell will diminish today. Building trade winds will produce a gradual increase in short-period waves to east facing shores during the next couple of days, peaking around Wednesday. A small, long-period south swell may arrive Tuesday, while a small, shorter-period south-southeast swell is expected over the next couple of days.

HFO Watches/Warnings/Advisories

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

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Data Courtesy of NOAA.gov