textproduct: Honolulu

SYNOPSIS

A band of moisture will exit the region this afternoon, decreasing shower coverage over the western islands later today. Windward and mauka areas could see numerous showers, especially in Kauai County. A more typical (drier but not dry) trade wind pattern will return this evening and continue into early next week.

SHORT TERM UPDATE

Showers have decreased over the area this morning, but should increase again briefly late this morning and into the afternoon. By this evening, showers will be on a downward trend as the area of moisture that brought significant rain to the Big Island yesterday moves out of the area. A minor forecast update will be out shortly to depict this scenario. No changes to the longer term forecast, as a return to relatively dry trades is still expected late today into tonight.

PREV DISCUSSION

Issued at 352 AM HST Wed Jun 3 2026 Early this morning, a band of moisture that produced substantial rainfall and minor flooding for portions of the Big Island yesterday has largely moved west of Maui County and the Big Island. As such, latest radar imagery shows that the majority of showers are now focused within the coastal waters off of leeward coasts. However, higher moisture content remains over the western end of the state. The early morning 12z upper air sounding from Lihue showed that the inversion height remains elevated at around 14,000 feet with around 2 inches of precipitable water, while the Hilo sounding shows that the inversion has significantly lowered to around 9,000 feet and precipitable water has reduced to around 1.5 inches.

The focus for enhanced shower coverage, with possible minor flooding, will be the western islands today. This will be followed by drier conditions statewide by this evening as the plume of moisture continues to move west of the region. A weak ridge aloft to the northeast will weaken over the next few days, and a new stronger closed upper ridge will develop to the north this weekend. This will help keep a strong surface high to our north, ensuring moderate to locally breezy trade winds continue throughout the next several days. Global models continue to indicate smaller pockets of moisture embedded within the trade flow will briefly increase trade wind shower activity from time to time through the rest of this week, but it will be difficult to time until closer to arrival. Therefore, periods of showers will continue, primarily focused along windward and mountain areas. Some days will see slightly more showers than others, and the overall pattern looks slightly wetter than normal for June. However, the risk for any significant flooding will remain low from Thursday well into next week.

AVIATION

Clouds and showers will linger over Kauai today as a convergent band slowly tracks away to the west. VFR conditions will prevail elsewhere. AIRMET Sierra for tempo mountain obscuration is in effect for windward Kauai, with conditions expected to improve later today.

AIRMET Tango is posted for moderate turbulence below 8000 feet all leeward portions of the islands, and should continue as breezy trades are forecast over the next several days.

MARINE

Fresh to strong easterly trades will prevail through at least the weekend as high pressure remains anchored far northeast of the islands. A Small Craft Advisory (SCA) remains in effect for the typically windier channels and waters around Maui County and Big Island through tomorrow, but the SCA will be extended in time and may need to be expanded to additional waters if trades strengthen any more. Trades may ease Tuesday.

A peaking south-southwest swell is producing surf well above the High Surf Advisory threshold and near the warning level of 15 feet this morning. Offshore NOAA buoys 51002 and 51004 registered swell of 6 to 7 feet at 17 seconds overnight, and nearshore PacIOOS buoys have been showing the swell at around 6 feet this morning as the swell peaks. The swell will begin to gradually lower by evening, with south shore surf likely dropping below the advisory threshold of 10 feet by Thursday afternoon. Surf will fall to moderate levels Friday and will fade Sunday, followed by a smaller pulse of south-southwest swell early next week.

Along north facing shores, a small medium-period north swell will arrive Thursday and and peak Friday before easing over the weekend. Surf along east-facing shores will gradually build to around seasonal average by Friday then hold into early next week.

HFO WATCHES/WARNINGS/ADVISORIES

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

Small Craft Advisory until 6 PM HST Thursday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.