textproduct: Honolulu

SYNOPSIS

Breezy trades will focus low clouds and showers across windward and mauka areas through the middle of next week. A plume of moisture moving south of the islands will increase rain chances over the eastern end of the state through Monday, followed by drier conditions through mid-week. Brewing disturbances within the tropics will need to be monitored for more organized development the next several days.

SHORT TERM UPDATE

Upper ridging centered far northeast of the state with its axis draped southwest over the region was the controlling feature to today's partly sunny and relatively dry conditions. Evening IR satellite imagery depicting an area of higher moisture southeast of the state that will track south of the island chain tonight. This more moist air will primarily pass by Big Island and graze the smaller islands...or be the impetus to more, mainly windward, showers into the early Sunday morning hours. Upper ridging will subtly back off the next couple of days. The result will be a deeper, more moist boundary layer over the state. This will produce a cloudier and wetter Sunday, especially for the windward communities of Big Island and Maui.

PREV DISCUSSION

Issued at 351 PM HST Sat Aug 8 2026 High pressure to the far northeast and a weak trough approaching from the southeast will continue to drive breezy trades across the state through the weekend. Satellite imagery shows mostly dry conditions persisting across the western half of the state this afternoon along with some passing high cirrus, and increasing low cloud and shower coverage over the eastern end. These clouds and showers moving into windward slopes of the Big Island marks the leading edge of a larger plume of moisture associated with the aforementioned westward-moving surface trough passing south of the state this weekend. Some of this moisture may track up the island chain to increase windward and mauka showers across Maui, Molokai, and possibly Oahu tonight into Sunday, though the highest rain chances remain centered over the Big Island. Forecast soundings indicate modest instability over the Big Island tomorrow. Combined with increasing tropical moisture and daytime heating, this may produce an isolated thunderstorm or two over interior slopes during the afternoon hours.

As the pressure gradient relaxes slightly in response to the surface trough weakening and moving farther westward away from the state, moderate to breezy trades are expected Monday through about Thursday. Drier air will fill in across the island chain midweek, dropping dew points and providing some relief from the mugginess.

Beyond Thursday, forecast confidence decreases, as local weather will depend on the possible development and progression of a tropical cyclone in the Central Pacific. The National Hurricane Center is monitoring an easterly wave about 1,400 miles east- southeast of the state, assigning an 80 percent probability of tropical cyclone development over the next 7 days. While it remains too early to discuss specific local impacts, this feature warrants close monitoring over the coming days.

AVIATION

Moderate to fresh trades expected for the next several days. Low cigs and SHRA should mainly impact windward and mauka spots. Isol IFR and some MVFR conds likely in heavier SHRA, otherwise VFR prevails.

AIRMET Sierra is in effect for mtn obsc for windward locations of all islands.

AIRMET Tango is in effect for mod turb downwind of island terrain. This AIRMET will likely be needed for next several days.

MARINE

Issued at 351 PM HST Sat Aug 8 2026 Fresh to locally strong trade winds will persist through at least Wednesday as high pressure remains anchored northeast of the state. A Small Craft Advisory remains in effect for the typical windy channels and waters around Maui County and the Big Island through Sunday afternoon. This advisory many need to be extended further, as borderline conditions will prevail through at least Wednesday. Later in the week, the focus will shift to the deep tropics southeast of the state. A tropical cyclone could develop and have an effect on local winds, seas and weather as early as Friday.

Continued small overlapping south-southwest swells will produce south shore surf near August average this weekend and near to above average Monday and Tuesday. A larger swell will arrive Tuesday night and may push surf to the High Surf Advisory level late Wednesday through Friday. This swell should slowly decrease next weekend.

Along east-facing shores, short-period trade wind swell will generate surf just below August average through Thursday. Depending on how potential tropical cyclone development plays out southeast of the islands, an increase in southeast swell is possible Friday and next weekend. Aside from wrapping trade wind energy, surf along north-facing shores will remain flat to tiny through the week.

Due to a combination of peak monthly high tides and water levels running higher than predicted in a few locations, minor coastal flooding will be possible around the afternoon high tide as early as Sunday, with peak conditions Monday through Wednesday.

HFO WATCHES/WARNINGS/ADVISORIES

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