textproduct: Honolulu

SYNOPSIS

A strong pressure gradient has developed over the state as a strong high sits north of the state and Major Hurricane Lowell passes roughly 450 miles south of Hilo. This gradient is generating very windy and gusty trades over Maui County, the Big Island, and over Oahu. Trades are expected to continue to strengthen across the state Thursday where portions of Kauai may be added to the wind advisory. Drier air is filtering so chances particularly during the overnight through early morning hours each day. The forecast remains uncertain for the upcoming Labor Day weekend due to both Lowell and Karina remaining in the central Pacific over the coming days.

SHORT TERM UPDATE

Latest satellite imagery loop shows the distinct eye of major Hurricane Lowell well south of the Big Island, along with all accompanying deep convection. Lowell is currently approximately 450 miles south of Hilo and moving west at 10 mph according to the latest 11 PM NHC advisory package. Across the islands, mainly light trade wind showers have been occurring with rain rates generally less than 0.10" an hour.

Winds have been rather gusty across much of the island chain this evening. Tight surface pressure gradients have developed with the state sandwiched between a 1030 mb surface high far north of Hawaii and the low pressure from Lowell's passing to the south. Winds have generally gusted between 40 and 50 mph over the most strong trade wind prone passes, ridgelines, and to the lee of terrain. A Wind Advisory remains in effect for select portions of Oahu, Maui County, and Big Island through Thursday afternoon. However, this product may need to be extended through early Friday morning.

Attention shifts late this weekend into early next week to the forecast track of Hurricane Lowell. The National Hurricane Center (NHC) latest forecast on Lowell has the system continuing a westward track far south of the islands over the next couple of days, before turning northward late this weekend and early next week as major hurricane. While confidence is not high there is a possibility that a major hurricane can impact the state next week. We continue to closely monitor this system and update forecast as necessary. Now is the time to make a plan for worst case scenario in order to be able to take action if and when needed.

PREV DISCUSSION

Issued at 425 PM HST Wed Sep 2 2026

A tight pressure gradient is developing over the state as Major Hurricane Lowell tracks west roughly 400 miles south of the Big Island this afternoon and a strong high remains far north of the state. Very windy and gusty trades have developed over Maui County and the Big Island and are anticipated to develop over Oahu this evening, thus have added portions of Oahu to the Wind Advisory. Portions of Kauai may need to be added to the Advisory Thursday as trade winds continue to strengthen across the state.

Current radar and satellite show clouds and showers have cleared significantly since this morning as drier air filters in. Expect typically trade wind showers to focus over windward and mauka areas, especially during the overnight and early morning hours with a few showers spilling over to leeward areas at times within the strong trade wind flow. This trend will carry in to the weekend with a slight uptick in showers expected Thursday night as a low level band of clouds and showers ride through the trades.

The National Hurricane Center (NHC) latest forecast on Lowell has the system continuing a westward track far south of the islands over the next couple of days, before turning northward late this weekend and early next week as major hurricane. While confidence is not high there is a possibility that a major hurricane can impact the state next week. We continue to closely monitor this system and update forecast as necessary. Now is the time to make a plan for worst case scenario in order to be able to take action if and when needed.

Meanwhile, Hurricane Karina is about 1360 miles east of Hilo this afternoon, and the latest forecast from the NHC has it moving west- northwest through Friday, before lifting further to the north over the weekend and weakening. As Karina moves northeast of the islands this weekend and early next week, it will help to disrupt the strong trade wind flow, helping our winds to return initially to more moderate levels. Early next week it could lead to lighter winds. Remnant moisture from Karina could significantly increase chances of showers over the weekend and interact with the moisture field with Lowell keeping cloudy and showery conditions into early next week. Due to the uncertainty with the forecast tracks of both Lowell and Karina this far out, confidence in the forecast is low as details of the forecast for this upcoming holiday weekend are still being flushed out.

Please visit the hurricanes.gov page for the official NHC forecast for Lowell and Karina.

AVIATION

VCSH along windward sides of the islands through this evening with cigs locally going down to MVFR. Elevated winds will remain through the night; moderate confidence in wind gusts over 30 kts at some TAF sites by Thursday afternoon. Otherwise, VFR conditions prevailing through the period.

Hurricane Lowell is forecast to pass far south of the island chain the next couple of days. On this westerly track, regional trade winds will remain strong per a tight pressure gradient between the hurricane and high pressure to the far north.

AIRMET Sierra has been issued for IFR and SHRA for KAUAI OAHU MOLOKAI MAUI through 20Z.

AIRMET Tango remains in effect for moderate low level turbulence south through west downstream of high terrain. AIRMET Tango will likely be in effect for the foreseeable future.

MARINE

Issued at 425 PM HST Wed Sep 2 2026 As a strong surface high persists far north of the Hawaiian Islands and interacts with Hurricane Lowell passing to the south, trade winds will strengthen across the coastal waters to become fresh to locally near gale force. A Small Craft Advisory (SCA) remains in effect for all Hawaiian Waters through Thursday night and will likely get extended into Friday. The offshore waters is currently seeing tropical storm conditions over the far southern waters while the core of hurricane force winds remains just outside the area through Thursday. A Tropical Storm Warning remains in effect for the far southern offshore waters.

While there is still plenty of uncertainty regarding the exact track of Lowell, confidence is fairly high that the southwest and western offshore waters will see Hurricane conditions. How close it gets to the state, is yet to be determined. As for Hurricane Karina, confidence is increasing that Karina will pass to the north and northeast of the state.

Swells from Hurricane Lowell will steadily fill in across rest of the island chain tonight into Thursday and will likely produce advisory level surf for south and southeast exposures throughout the state. Swells from Lowell will likely linger through next week and will gradually veer from southeast to south tonight through Thursday and eventually towards the 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. Additionally, the current moderate long period south swell will peak tonight then gradually decline through the rest of the week.

A large, medium-period east swell from Hurricane Karina will steadily fill in Friday into the weekend and will likely produce high end advisory level surf or warning level surf along east facing shores by this weekend.

FIRE WEATHER

Issued at 425 PM HST Wed Sep 2 2026

Trade winds will continue to strengthen and spread across the state tonight and remain strong and gusty into Friday. Gusts to, or over 50 mph, will be possible in the typical windy areas. Relative humidity values are forecast to remain too high for critical fire criteria to be reached, and fuels are currently rated as not critical. Therefore, the strong winds will not trigger fire weather watches or warnings. The trade inversion is forecast to be 6000 ft to 7000 ft today.

HFO WATCHES/WARNINGS/ADVISORIES

High Surf Advisory until 6 PM 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-Molokai West-Niihau-South Haleakala-South Maui/Upcountry-Waianae Coast.

Wind Advisory until 6 AM HST Friday for Big Island North-Big Island South-Big Island Southeast-Central Oahu-East Honolulu-Ewa Plain-Honolulu Metro-Kahoolawe-Kipahulu-Kohala-Koolau Leeward- Lanai Leeward-Lanai Mauka-Lanai South-Lanai Windward-Maui Central Valley North-Maui Central Valley South-Maui Leeward West- Maui Windward West-Molokai Leeward South-Molokai North-Molokai Southeast-Molokai West-Molokai Windward-South Haleakala-South Maui/Upcountry-Waianae Coast-Waianae Mountains-Windward Haleakala.

Small Craft Advisory until 6 AM HST Friday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Big Island Windward Waters-Kaiwi Channel-Kauai Channel-Kauai Leeward Waters-Kauai Northwest Waters-Kauai Windward Waters- Maalaea Bay-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters-Pailolo Channel.