A weak surface trough and its associated moisture plume over the western end of the state will shift northwest through Friday, bringing a slight uptick in shower activity as it passes through. Otherwise, a lighter background flow will allow for a sea/land breeze pattern to persist into the weekend with showers developing over leeward and interior areas each afternoon, followed by clearing at night. Then trade winds will gradually strengthen through next week, shifting the shower focus to windward and mauka areas.
A departing surface trough continues to make for windward showers across Kauai and Oahu this evening. A weakened trade wind pattern remains in place, leading to land/sea breezes across most sites, however a return to steady trades over the next several days is expected. VFR conditions are broadly expected to prevail, however windward sites may see periods of MVFR under occasional shower activity.
AIRMET Sierra remains in effect for Kauai through Maui County due to mountain obscuration from showers. Conditions are improving for Maui County as of this TAF issuance, but mtn obsc may linger longer for Kauai and Oahu as this system remains within the vicinity of the islands.
Issued at 311 PM HST Thu Jun 18 2026 Light to moderate trades will hold for the next few days as a weak surface ridge remains to the north and a broad surface trough continues to move west over the island chain the next few days. The weak trough is currently located between Oahu and Kauai waters and is producing some scattered showers over the coastal and offshore waters. Scattered showers will generally decrease over the coastal waters by Friday. Trades may increase slightly over the weekend as the trough dissipates, with more pronounced strengthening early next week as the ridge strengthens to the north.
A moderate, long period south swell is peaking at advisory levels this afternoon, thus a High Surf Advisory remains in effect for all south facing shores through early Friday morning. This swell should drop below advisory levels by Friday as the swell gradually fades late tonight into the weekend. A series of smaller south- southwest swells will fill in Sunday into the first half of next week and will maintain surf near seasonal averages through next week.
Tiny 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.
High Surf Advisory until 6 AM HST Friday 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-Niihau-South Haleakala-South Maui/Upcountry- Waianae Coast.
