West Kaua’i

Tonight: Breezy. Partly cloudy with isolated showers. Lows 67 to 72 near the shore to around 60 above 3000 feet. Northeast winds up to 20 mph. Chance of rain 20 percent.

Saturday: Mostly sunny. Breezy. Scattered showers in the morning. Highs 83 to 88 near the shore to around 74 above 3000 feet. East winds up to 20 mph. Chance of rain 50 percent.

Saturday Night: Partly cloudy. Breezy. Isolated showers after midnight. Lows 67 to 72 near the shore to around 60 above 3000 feet. East winds up to 20 mph. Chance of rain 20 percent.

South Kaua’i

Tonight: Breezy. Mostly cloudy with scattered showers. Lows around 71. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Saturday: Breezy. Mostly cloudy with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 80 to 87. Northeast winds 15 to 20 mph. Chance of rain 50 percent.

Saturday Night: Breezy. Mostly cloudy with scattered showers. Lows around 71. Northeast winds 10 to 20 mph. Chance of rain 50 percent.

Kaua’i Mountains

Tonight: Breezy. Mostly cloudy with showers likely. Lows 61 to 68 in the valleys to around 57 above 4000 feet. East winds up to 20 mph. Chance of rain 70 percent.

Saturday: Partly sunny. Breezy. Showers likely in the morning, then scattered showers in the afternoon. Highs 74 to 81 in the valleys to around 64 above 4000 feet. East winds 10 to 20 mph. Chance of rain 70 percent.

Saturday Night: Mostly cloudy. Breezy. Scattered showers in the evening, then showers likely after midnight. Lows 62 to 69 in the valleys to around 58 above 4000 feet. East winds up to 20 mph. Chance of rain 70 percent.

North Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 63 to 72. East winds 10 to 15 mph decreasing to up to 10 mph after midnight. Chance of rain 50 percent.

Saturday: Breezy. Partly sunny with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 76 to 85. East winds up to 20 mph. Chance of rain 50 percent.

Saturday Night: Partly cloudy in the evening then becoming mostly cloudy. Scattered showers. Lows 63 to 72. East winds up to 15 mph. Chance of rain 50 percent.

East Kaua’i

Tonight: Mostly cloudy with scattered showers. Lows 64 to 74. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Saturday: Mostly cloudy with scattered showers in the morning, then mostly sunny with isolated showers in the afternoon. Highs 72 to 84. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Saturday Night: Mostly cloudy with scattered showers. Lows 64 to 74. Northeast winds 10 to 15 mph. Chance of rain 50 percent.

Detailed Forecast

Synopsis

High pressure north of the islands will maintain breezy easterly trade winds through the forecast period. Clouds and showers will favor windward and mauka areas, particularly at night and during the early morning hours, with a few showers occasionally spilling into leeward areas due to the strength of the trades. Some shower development is also expected each afternoon over Kona slopes of the Big Island.

Discussion

High pressure north of the islands continues to produce breezy easterly trade winds across the state. Satellite imagery shows partly cloudy skies across the region this afternoon, with the typical distribution of clouds over most windward and mauka areas and the Kona slopes of the Big Island. Radar imagery also shows generally dry conditions with isolated showers embedded in the trade wind flow. Kauai remains an exception to our normal trade wind conditions, with mostly cloudy skies and scattered showers moving across the island this afternoon as an area of enhanced moisture lingers upstream.
Guidance continues to show high pressure shifting eastward tonight then northeastward on Saturday. This will maintain our breezy trade wind pattern through early next week. Trade may ease slightly during the middle to latter part of next week as a front passes north of the state. Otherwise, expect fairly typical trade wind weather with clouds and showers favoring windward and mauka areas, particularly at night and during the early morning hours. Due to the breezy trades a few of these showers will occasionally spill over into leeward areas. Will also see some afternoon shower development over the Kona slopes of the Big Island.

Aviation

Breezy trades will continue through the next several days. Low cigs and SHRA should be focused over windward and mauka areas with limited spillover to leeward areas. MVFR conds expected in heavier SHRA, otherwise VFR prevails.
AIRMET Tango remains in effect for mod low-level turb over all islands. This will likely be needed for the next several days due to the breezy trades.

Marine

Fresh to strong easterly trades will persist through early next week as a surface ridge remains anchored north of the islands. A Small Craft Advisory remains in effect for the typical windier waters and channels around Maui County, the Big Island, and Kauai. The advisory may need to be expanded to Maui County windward waters and the Kaiwi Channel as trades strengthen slightly during over the weekend.
Surf along south-facing shores will trend up above average this weekend as a long period SSW swell arrives. Forerunners will begin filling in this evening with surf peaking late Saturday through Sunday. This swell peaked above guidance at the American Samoan PacIOOS buoy Tuesday night into Wednesday, which will translate to a peak locally late Saturday into Sunday, likely driving surf to the advisory threshold. A gradual downward will follow early next week.
Surf along east-facing shores will remain rough and choppy with heights hovering around average each day.
Surf along exposed north-facing shores will remain small through the weekend, with mainly background short period NNE energy continuing. A long period NW swell arriving late Sunday will lead to the surf picking back up to near average levels as it peaks Monday. Expect this trend to remain steady Tuesday through midweek as another medium-period pulse out of the same direction arrives Tuesday night. Expect a downward trend through the second half of next week.

HFO Watches/Warnings/Advisories

Small Craft Advisory until 6 PM HST Saturday for Kauai Northwest Waters, Kauai Leeward Waters, Maalaea Bay, Pailolo Channel, Alenuihaha Channel, Big Island Leeward Waters, Big Island Southeast Waters.

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