A trough moving over the island chain from the west will bring clouds and showers to the state through tomorrow night. An accompanying upper level disturbance provides the instability for the chance for thunderstorms and locally heavy rainfall. Conditions are expected to improve Thursday or Friday, with trade winds returning this weekend.
Widespread SHRA continue to push over the central portion of the state this evening. The timing of the heaviest rain will be early tonight through much of the overnight hours for the western end and central portion of the island chain. MVFR/IFR cigs/vis are expected with the rainfall. TEMPO groups are included in most locales to account for a period of RA with IFR cigs/vis. There will likely be isolated instances of RA+. VCTS/TS not included due to low confidence at this time. By late tonight into early tomorrow morning, PHTO and PHKO will start to see rain moving in as the area of precip moves to the east.
Winds will remain generally weak through the forecast period. However, thunderstorms could bring brief gusty and erratic winds.
AIRMET Sierra for mountain obscuration remains in effect abv 025 for all islands due to the increase in low clouds and steady rain.
Issued at 323 PM HST Tue Oct 27 2026
A vigorous surface trough and possible elongated area of low pressure will move over coastal waters surrounding Maui County and Oahu tonight and Wednesday as a broad surface low meanders roughly 800 nm northeast of the islands. Expect moderate easterly winds to develop north of the trough and southeast to south winds to form south of the trough. Close to the trough, these winds could become locally strong, especially if a surface low deepens near the islands, and a Small Craft Advisory (SCA) is in place for waters around Maui County and Oahu through Wednesday. In addition, strong thunderstorms along the trough could produce erratic wind gusts in excess of gale force. The trough and possible low will weaken near the Big Island Thursday, allowing ridging to the north to drive moderate to fresh easterly winds over most waters and southerly winds near Big Island. The trough will move south of Big Island Friday, and moderate to locally fresh trades will prevail Friday night and Saturday. Stronger northeast winds may develop on Sunday and require an SCA.
A moderate northwest swell will decline late tonight and Wednesday, allowing surf to fall below seasonal average along north- and exposed west-facing shores. This swell will fade by Thursday. A small, short-period north-northeast swell will persist through much of the week, and may even become moderate Thursday and Friday with the arrival of reinforcing energy from the northeast. A larger long-period northwest swell will arrive late Saturday and may push surf above the high surf advisory threshold Sunday and Monday.
A series of overlapping south-southwest swells will continue through the weekend. The current swell is producing south shore surf near seasonal average, and additional pulses on Wednesday and Friday could produce above average surf.
Surf along most east-facing shores will be small through the first half of the week, but areas exposed to wrapping north to north- northeast swells will experience periods of moderate surf. A moderate northeast swell is possible Thursday and Friday.
Flood Watch through late Wednesday night for Big Island East-Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Big Island Summits-Central Oahu-East Honolulu-Ewa Plain-Haleakala Summit-Honolulu Metro-Kahoolawe-Kauai East-Kauai Mountains-Kauai North-Kauai South-Kauai Southwest-Kipahulu- Kohala-Kona-Koolau Leeward-Koolau Windward-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-Niihau-Oahu North Shore-Olomana-South Haleakala-South Maui/Upcountry-Waianae Coast-Waianae Mountains- Windward Haleakala.
High Wind Warning until noon HST Wednesday for Big Island Summits.
Small Craft Advisory from midnight tonight to 6 PM HST Wednesday for Kaiwi Channel-Kauai Channel-Maui County Leeward Waters-Maui County Windward Waters-Oahu Leeward Waters-Oahu Windward Waters- Pailolo Channel.
