Marine Weather and Tide Forecast for Manele, HI

SHORT TERM UPDATE
Radar and satellite imagery show isolated to scattered showers moving into mainly windward and mauka areas of the state this morning, and this activity is expected to continue over the next couple of hours. Looking just upstream, a plume of deeper moisture will arrive on the trades by sometime this afternoon for the eastern end of the state and work its way across the island chain.
This will result in a slight uptick in windward and mauka shower activity as this plume of deeper moisture rolls through. These showers may produce brief moderate downpours at times, but they will move through rather quickly, so flooding is not expected to be an issue. Otherwise, high pressure to the far north will gradually build through the weekend as it edges eastward, which will help to strengthen the trades to moderate to locally breezy levels.

PREV DISCUSSION
Issued at 334 AM HST Fri Oct 16 2026

Radar shows scattered windward and mauka showers across the state this morning. A large surface high continues to strengthen to our north. Aloft, a weak upper level low to our east will become a trough that stretches from southern CA all the way out to us. The trough will be weak, and apart from a slight increase in instability, we won't see much from it.

Several impulses of increased moisture will move toward and over the state, especially the eastern end, over the coming week. The first will move through this afternoon and evening, and reach all islands. The second should move over the area late Sunday through late Monday, boosting showers mainly across the eastern end of the state. Finally, another area may reach us next Thursday, but at this time range confidence is low. Models currently indicate the focus of this one would be on the eastern end.

Trade winds will remain moderate to breezy through the coming week, with the a slight increase possible Tuesday evening. A slight weakening may develop next Thursday, but as mentioned in the previous paragraph, at seven days out, confidence in that level of detail is low.

Finally, guidance indicates that the upper level trough extending from southern CA over to us may join with energy moving in from the northwest and strengthen toward the middle of next week. It is unclear at this time whether it will develop into a closed low or a stronger trough. Either way, it may draw tropical moisture northward toward the state and present a heavy rain threat.
Details should become clearer in a few days.

AVIATION
Gusty trade winds will continue today and tonight. Shower coverage will increase from east to west during the next 24 hours, initially favoring windward portions of the Big Island and Maui today, then spreading toward Oahu and Kauai later today and tonight. Brief MVFR ceilings and visibility are expected in passing showers, with VFR conditions prevailing between showers.

AIRMET Sierra for mountain obscuration has been cancelled for now. Increasing shower coverage may bring renewed mountain obscuration later today and tonight.

AIRMET Tango remains for moderate low level turbulence downwind of island terrain.

MARINE
Surface high pressure far north of the islands will strengthen as it drifts eastward through Saturday. Reinforcing high pressure will build far north of Hawaii on Sunday and will settle far northeast of the islands through early next week. Fresh to strong trade winds will prevail during this time, and a Small Craft Advisory (SCA) remains in effect for the typically windy waters around Big Island and Maui. The SCA has been extended through the weekend and may need to be expanded to additional waters.

A small northwest swell will continue to fade today as a moderate north-northwest swell arrives. Surf along north- and west-facing shores should build quickly and top out near or slightly above seasonal average during the peak of the swell late this afternoon into tonight, then slowly decline Saturday and Sunday as the dropping swell shifts more northerly. A smaller overlapping northwest swell should arrive at the same time and maintain small surf on Sunday. Both swells fade early next week.

A new long-periond south swell will peak today, keeping surf along south-facing shores just above seasonal average through tonight. This swell will slowly decline Saturday through early next week.

Surf along east-facing shores will gradually increase over the next couple of days as trade winds strengthen over the region.
Expect some wrap from the moderate north-northwest swell Friday afternoon into Saturday. This swell along with developing rough trade wind swell will produce east shore surf above seasonal average Sunday through early next week.

FIRE WEATHER
Issued at 334 AM HST Fri Oct 16 2026

Surface high pressure north of the islands will produce moderate to breezy trade winds for the next few days. RH levels look to remain out of critical fire threshold ranges. The stronger trade winds will mainly impact higher elevation areas with even higher minimum humidity levels. Inversion heights should range from 6,000 to 9,000 feet today.

HFO WATCHES/WARNINGS/ADVISORIES
Small Craft Advisory until 6 AM HST Monday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.