textproduct: Honolulu

SYNOPSIS

Slightly weaker trade wind flow today with a few light windward showers. Wednesday into Thursday, light easterly flow will lead to the development of sea/land breezes. Thus, most cloud cover and shower activity will be limited to interior and mountain areas during the afternoons. In addition, deeper moisture moving in from the southeast Wednesday through Friday should bring increased shower chances to the Big Island and Maui.

SHORT TERM UPDATE

Issued at 930 AM HST Tue Jun 16 2026

The forecast remains on track this morning, with isolated windward showers embedded within moderate trade wind flow. No major updates to the forecast have been made at this time.

PREV DISCUSSION

Issued at 310 AM HST Tue Jun 16 2026

Current satellite and radar imagery shows some isolated to scattered showers moving in on the trade impacting windward and mauka locations with some spillover over to leewards areas. Moderate trades are expected across the state today due to a high continuing to move far to the northeast.

By Wednesday, the local pressure gradient is expected to weaken even further, with background winds becoming light and variable. Daytime heating, combined with weak surface flow, will lead to daytime sea breezes and nighttime land breezes. Clouds and showers should mainly be limited to over the island interiors and mountainous terrain, particularly during the day. By Wednesday night, however, global forecast models remain consistent in a pocket of deeper moisture associated with a weak surface trough moving northward from the southeast towards the Big Island. This feature could act to increase shower coverage, especially along eastern portions of the Big Island. Long range models continue to push this band of moisture up through Maui County and, to a lesser extent, Oahu on Thursday into Friday before lifting it northward. Light southeast flow, combined with this batch of moisture, could lead to an increase in shower activity over the islands interiors during the afternoons. More typical trade wind weather should return by this weekend.

AVIATION

Issued at 310 AM HST Tue Jun 16 2026

Moderate trades today before weakening Wednesday. Low cigs and SHRA will impact windward an mauka locations. MVFR conds possible otherwise VFR prevails. Weakening trades should allow for sea/land breeze development on Wednesday.

No AIRMETs in effect.

MARINE

Issued at 310 AM HST Tue Jun 16 2026

Moderate to locally fresh trade winds will gradually ease to light to moderate speeds through the end of the week as a trough to the northwest weakens the ridge to the north. The ridge will strengthen over weakened as the troughs weaken and lifts far north, allowing fresh to moderate easterly trades to return.

The current large, long period south southwest swell will continue to slowly decline as the swell slowly fades. Swell heights remain elevated as the swell period has begun to decline. The High Surf Warning has been downgraded to a High Surf Advisory (HSA) through tonight for all south facing shores. Another south southwest swell is expected to fill in Wednesday night into Thursday that could push surf back up to HSA levels.

Surf along north facing shores will remain flat to tiny through the forecast period. Surf along east facing shores will remain below average as easterly trade winds ease through the end of the week.

A Coastal Flood Statement remains in effect for minor coastal flooding of vulnerable low-lying coastal roadways, docks, boat ramps and other coastal infrastructure due to King Tides. King Tides combined with water levels that are running higher than predicted will lead to minor flooding potential around the daily peak tide, which will be during the late afternoon and early evening hours, through today and possibly Wednesday. While minor coastal flooding is expected along all shorelines, the combination of the large south southwest swell and peak daily high tides will make low-lying coastal areas along south and west shores susceptible to more widespread coastal flooding through this evening.

A Marine Weather Statement also remains in effect due to the large, long-period south southwest swell producing harbor surges and breaking waves near harbor entrances along south and west-facing harbors.

HFO WATCHES/WARNINGS/ADVISORIES

High Surf Advisory until 6 AM HST Wednesday for Big Island South- Big Island Southeast-East Honolulu-Ewa Plain-Honolulu Metro- Kahoolawe-Kauai South-Kauai Southwest-Kipahulu-Kohala-Kona-Lanai Leeward-Lanai South-Maui Central Valley South-Maui Leeward West- Molokai Leeward South-Molokai Southeast-Niihau-South Haleakala- South Maui/Upcountry-Waianae Coast.