Photo Credit: Sebastien Gabriel

West Kaua’i

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South Kaua’i

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Kaua’i Mountains

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North Kaua’i

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East Kaua’i

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Detailed Forecast

Synopsis

Light trade winds will deliver just a few windward showers today, with afternoon sea breezes leading to a few leeward clouds. Winds will continue to diminish tonight, with light and variable winds and dry weather through Friday. Expect mostly clear nights and mornings that give way to interior clouds in the afternoons, with isolated showers. Trade winds are expected to return next weekend.

Discussion

A relatively weak (1020 mb) surface high centered about 1000 miles WNW of Kauai is supporting a light trade wind flow this morning, although many land areas have light and variable winds. Mostly dry conditions continue to prevail, as a diffuse band of shallow moisture near Kauai has dissipated. Satellite shows increased low- level cloudiness E of Maui and the Big Island as a low-level trough passes S of the islands. Radar shows a few showers embedded, but they are not amounting to much in the way of measurable rainfall.
Trades will decline today as the surface ridge to the N is eroded and pushed southward. The moisture near the Big Island will help to fuel a few showers there, with little rainfall elsewhere as moisture remains limited and ridging aloft maintains stable conditions.
The high will dissipate on Tuesday, and a surface ridge will extend over the islands from the E, with trade winds becoming light and variable starting tonight. The light winds will allow for mostly clear skies during nights and mornings, with some interior and upslope clouds in the afternoons. With a strong mid-level ridge building overhead, rainfall chances will be minimal. This pattern is expected to persist through Friday.
A front will near Kauai by next weekend. In what may be a large- scale pattern change, strong high pressure building NW of the front appears poised to support increasing trade winds next weekend that have the potential to become strong. Long range guidance suggests the front could bring some windward-focused rainfall to parts of the chain in just over a week.

Aviation

Light to moderate trade winds today will transition to light southeasterly winds from Tuesday onward, as another cold front approaching the islands from the northwest breaking down the ridge over the Hawaii Region. Expect local scale land and sea breeze winds for most island areas. Afternoon sea breezes will build clouds over island mountain and interior sections each day with clearing land breezes at night.
No AIRMETs in effect.

Marine

A surface ridge located about 300 nm north of Lihue will maintain light to moderate trade winds today. A cold front approaching the region from the north-northwest will cause the ridge to weaken, and shift down closer to the state by Tuesday. This will result in light and variable winds near the western islands, while light to locally moderate east-southeast to southeast winds will develop in the vicinity of the eastern islands. The latest forecast indicates strengthening northeasterly trade winds may spread over the coastal waters starting late Friday as a surface high pressure system builds far northwest of the state.
The current north-northwest (340 degrees) swell continues to produce moderate surf along most exposed north and west facing shores early this morning. This swell has been dropping at the buoys northwest of Kauai, so we expect surf to gradually lower along north and west facing shores from later today and tonight through Tuesday. A new medium-period north-northwest (330 degrees) swell arriving late Wednesday may produce a modest increase in surf along exposed north and west facing shores from Wednesday night into Thursday. This swell will gradually lower from Thursday night through Friday.
The series of late season swells originating from The Southern Hemisphere will continue this week. The current south (180-190 degrees) swell will maintain modest surf along south facing shores today, with a gradual decline from late Tuesday through Wednesday. A small, long-period southwest (210-220 degrees) swell arriving Thursday combined with swell sources from the south (180 degrees) and south-southeast (160 degrees) will likely maintain small surf along south facing shores from Friday into next weekend. Elsewhere, surf along east facing shores will continue to be small this week due to the lack of a significant fetch of trade winds upstream of the islands.
Higher than predicted water levels have been observed across the Hawaiian Islands this weekend. Minor coastal flooding is possible during the early morning high astronomical tides early this week, with the highest tides likely occurring early this morning. Therefore, a Coastal Flood Statement remains in effect through Tuesday morning for all vulnerable coastal areas across the state.

HFO Watches/Warnings/Advisories

None.

Data Courtesy of NOAA.gov