Trade winds will gradually strengthen statewide, and rainfall across Big Island will increase over the next couple of days as Tropical Depression Fifteen-E intensifies south of the Big Island. The system is forecast to move near the Big Island on Friday and Saturday as a hurricane, bringing potentially damaging winds and heavy flooding rainfall. While uncertainty in the track of the hurricane is higher than normal, the latest forecast calls for system to move westward late Saturday and Sunday, keeping some threat for significant impacts through the weekend. Interests across the State of Hawaii should monitor the progress of Fifteen-E.
Breezy trade winds into Thursday. Strong gusts to around 35 knots expected at PHMK and PHOG this afternoon. Shower activity will increase across the Big Island this afternoon with some potential for isolated thunderstorms as a tropical disturbance remains just to our south. Shower activity will increase moving northwards late Wednesday into early Thursday with highest confidence in showers extending up to Molokai by early Thursday morning. MVFR ceilings and visibility are most likely across the Big Island where rainfall will be heaviest but periods of reduced ceilings/visibilities within heavier showers will be possible across the rest of the islands.
AIRMET Sierra is in effect for mountain obscuration and may continue into the morning.
AIRMET Tango is in effect for low level turbulence downwind of island terrain.
See main discussion for more info on Tropical Depression 15-E.
Issued at 415 AM HST Wed Sep 23 2026 The gradient between the subtropical high to the northeast Tropical Depression 15-E to the south-southeast will cause moderate to fresh trade winds across the Hawaiian coastal waters through today. A Small Craft Advisory (SCA) is in effect for the typical windy waters of Maui County and the Big Island through Friday morning. Tropical storm and/or hurricane watches and warnings may come into play Thursday through the weekend. Rainfall and thunderstorms will increase as the system nears, particularly across the eastern waters.
Surf along south facing shores will decrease as the current south-southwest swell fades. A moderate southwest swell will build in around Friday into the weekend building surf back up across south and west facing shores nearing high surf advisory criteria. Tropical Depression 15-E is expected to intensify to a hurricane over the next couple of days and will likely produce very large and rough surf along south facing shores on the Big Island.
A small, short period, north-northwest swell will fade through today. Another small northwest swell will fill in this weekend keeping surf slightly elevated along north and west facing shores.
East facing shores will maintain rough, short period wind waves generated from the breezy trade winds.
Flood Watch through Saturday afternoon for Big Island East-Big Island Interior-Big Island North-Big Island South-Big Island Southeast-Big Island Summits-Haleakala Summit-Kahoolawe-Kipahulu- Kohala-Kona-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-Windward Haleakala.
Small Craft Advisory until 6 AM HST Friday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.
