West Kaua’i

Tonight: Partly cloudy with isolated showers. Lows around 74 near the shore to around 64 above 3000 feet. Northeast winds up to 15 mph. Chance of rain 20 percent.

Sunday: Sunny and breezy. Isolated showers in the morning. Highs 85 to 90 near the shore to around 76 above 3000 feet. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 20 percent.

Sunday Night: Mostly clear. Isolated showers after midnight. Lows around 73 near the shore to around 64 above 3000 feet. East winds 10 to 15 mph. Chance of rain 20 percent.

South Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 69 to 77. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Sunday: Mostly sunny. Breezy. Scattered showers in the morning, then isolated showers in the afternoon. Highs 80 to 89. Northeast winds 15 to 20 mph. Chance of rain 40 percent.

Sunday Night: Partly cloudy in the evening then becoming mostly cloudy. Breezy. Scattered showers. Lows 69 to 77. East winds 15 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with numerous showers. Lows around 68 in the valleys to around 60 above 4000 feet. East winds 10 to 25 mph. Chance of rain 70 percent.

Sunday: Breezy. Partly sunny with scattered showers. Highs 75 to 82 in the valleys to around 68 above 4000 feet. East winds 10 to 25 mph. Chance of rain 50 percent.

Sunday Night: Breezy. Mostly cloudy with scattered showers. Lows 65 to 70 in the valleys to around 60 above 4000 feet. East winds 15 to 20 mph. Chance of rain 50 percent.

North Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 64 to 75. East winds up to 20 mph. Chance of rain 50 percent.

Sunday: Breezy. Mostly sunny with scattered showers. Highs 71 to 86. East winds up to 20 mph increasing to 10 to 20 mph in the afternoon. Chance of rain 40 percent.

Sunday Night: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 64 to 75. East winds 10 to 15 mph. Chance of rain 50 percent.

East Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows 65 to 76. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Sunday: Breezy. Partly sunny with scattered showers. Highs 78 to 85. East winds 10 to 20 mph. Chance of rain 50 percent.

Sunday Night: Breezy. Mostly cloudy with scattered showers. Lows 65 to 76. East winds 15 to 20 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

A high pressure system will linger north to northeast of the Hawaiian Islands through the middle of next week, producing moderate to breezy trades with minor fluctuations in speed. Brief increases in showers, most noticeable tonight and Sunday night, will give way to drier trades for most of next week. There is still significant uncertainty in next weekend's weather.

Discussion

Radar and satellite show isolated showers across the windward areas of most islands, along with the usual trade wind pattern of mostly cloudy skies windward and partly cloudy to mostly sunny leeward. Winds were mainly out of the east or northeast, averaging 10 to 20 mph, with gusts to near 30 mph in a few places.
An evolving but basically persistent surface high pressure system to out north (sometimes northeast) will be with us for the next week. This should keep the trades blowing at moderate to breezy levels. There remains some uncertainty concerning the possible development of a surface low near the islands Friday, but ensembles are not giving a clear indication of what, if anything, might form.
In the meantime, two brief periods of enhanced showers appear to be on the way – one tonight and another Sunday night. There are no indications that heavy rain or flooding is likely. After that, we are in for a period of relatively dry trades as we await anything that might develop late in the week. Winds should remain strong enough to keep any showers moving fast enough to occasionally bleed over to leeward areas, but any rainfall amounts there will be light.

Aviation

VA SIGMET November in effect for Mt. Kilauea eruption in the south-central portions of Big Island. See VA SIGMET November for more detailed information. Since the eruption has subsided, and based on overall wind trajectory, no ash threat near terminals. SIGMET November is likely to be cancelled within the next 6 hours.
Otherwise, breezy trades will continue with isolated MVFR ceilings and visibility in any passing shower, mainly windward and mountain areas.
AIRMET Sierra may be needed tonight to account for mountain obscuration development in windward areas.
AIRMET Tango will continue into tomorrow for tempo moderate turbulence downwind of terrain below 9000 ft.

Marine

High pressure north of the islands maintains fresh to strong trades well into next week. The Small Craft Advisory (SCA) has been expanded in coverage to include Oahu and Kauai waters as trades are forecast to strengthen modestly tonight and tomorrow.
A mix of short period NNW swell which peaked at the outer buoys early this morning, and declining mid- long period swell (12 to 16 seconds) will keep small surf in place through tomorrow. Both of these swells drop off by Monday, allowing surf to drop to tiny levels through much of the week before a small northwest arrives towards the end of the week.
A mid to long period south-southwest swell (15 seconds) will keep above average surf in place tonight over south shores, then decline tomorrow and remain small through much of the week with background south swells. A small long period swell is possible next weekend.
Rough trade wind swell will produce above average surf for E shores through Tuesday before declining with weakening trades mid- week. Expect some wrap of NNW swell for exposed shorelines through tonight.

Fire weather

Fire weather conditions will remain below critical fire thresholds into the first half of next week. Breezy winds and minimum humidity levels will not align to reach critical levels in any of our fire weather zones. The subsidence inversion heights near Maui and the Big Island will range from 6,500 to 8,000 feet through Sunday.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 AM HST Monday for Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters, Kaiwi Channel, Kauai Channel, Kauai Leeward Waters, Kauai Northwest Waters, Kauai Windward Waters, Maalaea Bay, Maui County Leeward Waters, Maui County Windward Waters, Oahu Leeward Waters, Oahu Windward Waters, Pailolo Channel.

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Data Courtesy of NOAA.gov