textproduct: Honolulu

SYNOPSIS

Showers and isolated thunderstorms will spread over the western half of the state tonight and become heavy over central portions of the state Sunday into Sunday night. Flash flooding is possible. The heaviest rain is currently anticipated over Oahu and Molokai, and possibly Kauai.

SHORT TERM UPDATE

Issued at 814 PM HST Sat Apr 11 2026

The current forecast remains well on track, highlighting light winds through the next several days. Observations have shown light rainfall across the Hawaiian Islands, particularly across Maui and the Big Island, but amounting to under five hundredths of an inch of precipitation. Latest radar imagery depicts shower activity moving into the western islands, which lines up well with the current forecast. A Flood Watch remains in effect for all islands through Monday afternoon. Further analysis as this evolves will be shown on the morning update. Therefore, no amendments will be made this afternoon.

AVIATION

An unstable band of deep tropical moisture will move up from the south under an upper level disturbance. Weather conditions will destabilize later tonight, producing widespread MVFR and isolated IFR conditions statewide with low clouds, showers and thunderstorms from early Sunday morning through Monday. Light and variable winds will prevail at all airfields.

AIRMET Sierra remains in effect for mountain obscuration above 1500 ft for Oahu, Molokai and Lanai. Mountain obscuration coverage will likely be expanded overnight as showers develop.

MARINE

Issued at 814 PM HST Sat Apr 11 2026

A surface trough will linger in the vicinity of the central islands into early next week, keeping moderate to fresh southeasterly winds to its east, and light and variable winds to its west. This weak surface boundary along with an upper level disturbance moving into the region may help to bring another round of showers and isolated thunderstorms tonight through Sunday. As the surface trough lifts north and high pressure to the northeast begins to takes over at the surface, gentle to moderate easterly trades will gradually develop across the Hawaiian coastal waters by the end of next week.

A medium-period south swell will gradually decline through Monday. By Tuesday, however, a new south swell will arrive, once again providing a boost to surf along south facing shores through mid week before gradually subsiding into the weekend.

A moderate, short to medium-period northwest swell generated by the gale force low to the northwest filled in early this morning and is providing small to moderate surf to north and west facing shores this afternoon. Another northwest reinforcement will arrive on Sunday and maintain small to moderate surf through the weekend, followed by a decline in northwest swell energy next week.

Surf along east facing shores remains below seasonal average with lighter than average trade winds near and upstream of the islands forecast through next week.

HFO WATCHES/WARNINGS/ADVISORIES

Flood Watch through Monday afternoon 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.