Marine Weather and Tide Forecast for Ko Olina, HI

DISCUSSION
Currently at the surface, a weak diffuse trough of low pressure is located just west of Kauai, while a 1031 mb high is centered around 1750 miles northeast of Honolulu. Winds remain light across much of the state, with land breezes present or developing in most areas. Infrared satellite imagery shows mostly cloudy conditions across much of the state, with some pockets of lesser cloud coverage over the eastern islands. Radar imagery shows diminishing daytime heating driven showers, with most shower activity transitioning out over the adjacent coastal waters. Main short term focus revolves around the potential for heavy rain and thunderstorms during the next couple days.

The weak trough of low pressure will shift slowly eastward tonight, then settle over the smaller islands Monday and Tuesday.
Winds will change little during this time, with land and sea breezes dominant over most of the state. The troughing over the islands will gradually dampen out during the middle and latter part of the week as high pressure builds to the north. This should allow a gradual return and strengthening of the trade winds across the state, with the trades reaching breezy levels Friday through next weekend.

As for the remaining weather details, a land/sea breeze pattern will remain in place during the next couple days, with showers favoring interior and leeward areas during the afternoon and evening hours, and remaining mostly over the coastal waters or areas near the immediate coast at night. The airmass will over the state will remain moist and unstable Monday and Tuesday as a disturbance aloft dives southward over the state. This should continue to bring some locally heavy showers and a few thunderstorms to the island chain, particularly during the afternoon hours. A return to more typical trade wind weather featuring mainly windward and mauka showers appears take hold Wednesday, with this pattern then persisting through next weekend.

Volcanic emissions and light background southeast flow will keep vog in place over most of the state through Tuesday. The returning trades should clear the vog out beginning likely keep vog across the state through the next couple of days. Then as trade winds return, the vog will likely clear out of the smaller islands for the latter half of the week.

AVIATION
A low pressure trough over the islands will allow for an unsettled land and sea breeze pattern to persist across the state through Tuesday. Sea breezes will develop during the afternoons and lead to showers and a slight chance of thunderstorms over mainly interior regions, followed by clearing with land breezes at night. MVFR/IFR ceilings and visibility can be expected with some of the more robust activity, otherwise, VFR conditions will prevail.

No AIRMETs are currently in effect.

MARINE
A trough of low pressure near Kauai continues to weaken the high pressure ridge over the eastern Hawaiian Islands. This diffuse trough may bring some heavier showers and thunderstorms to the nearby coastal and offshore waters. This boundary is expected to slowly shift east over the next 24 hours, increasing the potential for showers and thunderstorms over the coastal and offshore waters. Light and variable winds will continue into the Tuesday. Trades will build back in from Wednesday onward as a high pressure system builds in north of the Hawaii Region.

A small long period northwest swell appears to have peaked, and will now fade into Tuesday. Surf along north and west facing shores should remain near or below average levels for this time of year. By Thursday, a medium long period north-northwest swell is expected to arrive, producing surf that may approach advisory levels.

Multiple small early season south swells will maintain small background southerly energy through the middle of this week. A bump up in south swell energy is expected to arrive late Thursday and last through next weekend. Weak upstream trade wind flow will keep surf along east facing shores near or below seasonal averages.

HFO WATCHES/WARNINGS/ADVISORIES
None.