textproduct: Honolulu

SYNOPSIS

Expect decreasing wind speeds Saturday and Sunday as a low pressure trough moving into the Central Pacific basin weakens the ridge north of the state. Periods of showers will favor windward and mountain areas, with brief passing showers over leeward zones. Monday, Hurricane Lowell is forecast to move close to Kauai County Monday night. It is expected to remain a major hurricane through Monday morning, then weaken as it moves north toward and then past the state. Weather impacts such as high surf and heavy rain are forecast to extend hundreds of miles from the center of Hurricane Lowell, potentially impacting each of the islands.

SHORT TERM UPDATE

As of the new 5 PM HST update, Lowell is once again a Category 5 hurricane, with top sustained wind speeds of 160 mph. The forecast track has held steady, taking it west of the state Monday night. Impacts may be felt across the state from heavy rain and large surf, even though it is not expected to make landfall at this time.

PREV DISCUSSION

Issued at 330 PM HST Fri Sep 4 2026 Radar and satellite show isolated trade showers moving across windward and mauka areas of each island this afternoon, along with mostly sunny skies leeward and partly to mostly cloudy skies windward. Winds were breezy, averaging 10 20 mph with gusts to 30 mph.

Hurricane Lowell is roughly 620 miles south of Kauai and continues to drift slowly westward this afternoon. A gradual decrease in the forward speed of Lowell remains in the forecast for the next day or two, followed by a turn to the northwest Saturday and north-northeast Sunday. The latest information from NHC (as of 11 AM HST) has Lowell as a Category 4 storm with maximum sustained winds of 150 mph. The forecast track remains west of Kauai County, but certainly close enough to warrant our constant attention.

There remains a risk for high surf, strong winds,and heavy rainfall for all islands of Hawaii, and especially Niihau and Kauai. Deep tropical moisture will advect northward across all island, producing warm and humid weather conditions. Heavy rainfall is expected to begin late Sunday and last into Tuesday.

Initial storm total rainfall estimates range from 2 to 8 inches statewide. With a significant period of south to southeast winds forecast, we expect locally higher amounts (around 10 inches) along south and southeast slopes. Please continue to closely monitor the weather forecast for early next week as the track and associated impacts with Hurricane Lowell may change over time.

High pressure builds back over the islands from Tuesday afternoon onward as a wet trade wind pattern with periods of passing showers sets up across the state into the end of next week. A moist area left from the remains of Karina is now modeled to move through the area Wednesday afternoon through Wednesday night, possibly providing an especially wet period.

AVIATION

Issued at 330 PM HST Fri Sep 4 2026 A breezy and stable trade wind flow will ease slightly on Saturday as Hurricane Lowell, currently centered about 600 miles 600 miles south of Kauai, moves slowly westward and allows the local pressure gradient to slightly relax. AIRMET Tango remains in effect for moderate low-level turbulence south through west of terrain and will likely remain posted for the same areas through Sunday.

A narrow band of moisture that was draped across windward areas earlier today has largely dissipated this afternoon, leaving only windward Big Island under AIRMET Sierra for mountain obscuration. Borderline conditions will persist on windward Big Island into tonight. Isolated MVFR conditions are expected over windward portions of all islands Saturday, while VFR prevails leeward.

MARINE

Issued at 330 PM HST Fri Sep 4 2026 A surface high persists north of the Hawaiian Islands and will slowly drift east through the weekend. Currently, Hurricane Lowell is passing near 520 nm south to southwest of the islands as it continues to track west. The interaction between the two has kept trade winds fresh to locally strong across the all coastal waters zones. A Small Craft Advisory (SCA) is in effect for all coastal waters through tonight and has been trimmed back on Saturday for only the windier waters and channels around Maui County and the Big Island through Saturday afternoon. As Lowell begins its expected turn northward this weekend, by early next week winds are likely to veer to the southeast to south with the strongest winds over the western end of the state.

Confidence has grown with the latest updates from the National Hurricane Center for the potential for hurricane conditions in the offshore waters west of 160W on Sunday through potentially Tuesday. How close it gets to the state, is yet to be determined. As for Hurricane Karina, it is expected to weaken and pass to the north and northeast of the state.

Southerly swells from Hurricane Lowell will keep surf elevated above High Surf Advisory (HSA) conditions through Saturday. A large, medium- period east swell is filling in from Hurricane Karina producing HSA level surf along east facing shores. The HSA is in effect for all south and east facing shores of all islands as well as the west facing shores of the Big Island through Saturday afternoon and will likely be extended.

The swell from Lowell will gradually veer from south to southwest early next week. While the forecast for swells and seas for next week will highly depend on the eventual track and intensity of Lowell, confidence is beginning to increase for the potential of extra- large surf (exceeding warning levels) along south and western exposures early next week. Coinciding also with monthly high tides, this will create the potential for impacts to harbor entrances, channels, as well as coastal properties and infrastructure including roadways.

FIRE WEATHER

Issued at 330 PM HST Fri Sep 4 2026 Periods of passing showers will mainly impact windward and mountain slopes through early Sunday. Considerably more showers are likely over most areas from Sunday afternoon into early next week. The temperatures inversion heights near Maui and the Big Island will range from 6,000 to 7,000 feet elevation tonight and Saturday.

HFO WATCHES/WARNINGS/ADVISORIES

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

Small Craft Advisory until 6 AM HST Saturday for Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters- Kauai Northwest Waters-Kauai Windward Waters-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters.

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