textproduct: Honolulu

SYNOPSIS

Lighter background winds will support daytime sea breezes and nighttime land breezes today through Friday. Thus, most cloud cover and shower activity will favor interior and mountain areas during the afternoons. Deeper moisture associated with a weak trough will move northward from the southeast through Friday, and will briefly increase shower chances island-by-island as it weakens. A more typical trade wind pattern will return late this weekend into early next week.

SHORT TERM UPDATE

Radar shows isolated shower activity over the western half of the state, along with scattered to numerous showers advancing into windward areas of the Big Island, associated with a weak surface trough approaching from the east. This surface trough tracking over the eastern end of the state this morning will continue to bring increased shower coverage to the Big Island through the day, spreading to Maui later this afternoon or evening. With light to moderate easterly winds across the region today, isolated sea breezes are expected to develop by this afternoon, bringing clouds and showers to interior and leeward areas. The current forecast remains on track, so no changes were made for this mid-morning update besides the cancellation of the High Surf Advisory, covered in more detail in the Marine section below.

PREV DISCUSSION

Issued at 304 AM HST Wed Jun 17 2026

Latest satellite and radar imagery shows isolated to scattered showers across the region. More persistent showers are moving onto and over the Big Island as a weak trough continues its march up the island chain. The trough should be near Maui tonight and possibly near or over Oahu on Thursday afternoon. As this weakening trough moves up the island chain expect a slight increase in showers before the trough moves away.

A series of fronts will move across the North Pacific well north of the island chain. This should disrupt the moderate trades weakening them through Friday. This should lead to sea/land breezes for the next few days. Clouds and showers should mainly be limited to over the island interiors and mountainous terrain, particularly during the day. The exception being the previously discussed weakening trough moving across the island chain.

After a brief period of east-southeasterly flow Saturday, moderate easterly trades will return during the second half of the weekend. Some light windward and mauka showers will return but fairly dry conditions will keep the showers limited.

AVIATION

Weak background flow will allow afternoon sea breezes and overnight land breezes to take place across the state. This will allow cloud and shower development over island interiors in the afternoon. An oncoming surface trough will continue impacting windward sections of the Big Island with light to moderate showers. The trough could also enhance shower activity over windward Maui later today. Primarily MVFR conditions are expected within showers, and brief IFR is possible under heavier showers. VFR will prevail elsewhere.

AIRMET Sierra is currently in effect for mountain obscuration across windward Kauai and Big Island. These conditions will likely last through today, and could be expanded to include other islands.

MARINE

Trade winds will be mostly at gentle to moderate strength during the next few days as the surface ridge to the north remains weak and a broad surface trough moves over the islands. The weak trough is producing numerous showers across most Big Island waters this morning and will slowly move to the northwest during the next few days. Trades will gradually strengthen Sunday and Monday as the trough dissipates and high pressure builds to the north.

A series of southern hemisphere swells will continue to move through the area during the next week, though smaller than the recent large event. The High Surf Advisory finally came down early this morning, and the current south swell will remain on a very slow decline today, with PacIOOS buoys recently reporting 3.5 to 4 feet at 14 seconds. A fresh overlapping south-southwest swell will arrive overnight and will produce surf around the High Surf Advisory threshold of 10 feet on Thursday. There is no sign of the new swell on the NOAA buoys south of the islands this morning, and we will be able to get a better handle on potential surf heights later today and tonight. This swell will decline Friday, and a series of smaller south-southwest swells will maintain surf around seasonal average this weekend into early next week.

Small surf will prevail on north and east shores through most of the coming week. A slight increase in east shore surf is expected around next Tuesday or Wednesday as trade winds build across the region.

HFO WATCHES/WARNINGS/ADVISORIES

None.