Increased trade winds Thursday and Friday combined with dry conditions will elevate the fire weather threat for the end of the work week. Most likely locations for any occasional showers will be over the windward and mauka areas through Friday. For the weekend, we're continuing to monitor Potential Tropical Cyclone One-C. Residents and visitors should prepare now for potential tropical cyclone impacts this weekend. Please monitor www.hurricanes.gov for the latest information.
Breezy trade winds will gradually strengthen through Friday. Scattered showers will focus over mostly windward and mountain areas, especially during the evening/overnight hours. Some showers will spill over to leeward areas. Expect mostly VFR during the day with periods of MVFR especially during the overnight and in showers.
AIRMET Sierra for mountain obscuration may be needed for windward/mauka locations overnight through Thursday morning as shower coverage increases. AIRMET Tango may also be needed overnight or Thursday for moderate turbulence immediately south and west of mountains due to strengthening low-level winds.
Issued at 356 PM HST Wed Aug 12 2026
High pressure to the far northeast will slowly drift into a position just north of the Hawaiian Islands into the weekend, producing moderate to locally strong trade winds across the region. A Small Craft Advisory (SCA) remains in place through Thursday afternoon for the windier waters and channels around Maui and the Big Island. As the high builds north of the state, the trade winds will strengthen Thursday into Friday, which will likely cause the SCA to expand in coverage by Friday.
The weather pattern will change significantly this weekend as we anticipate the development of Potential Tropical Cyclone One-C, currently around 700 NM east-southeast of the Big Island. Marine interests should be prepared for potential tropical cyclone impacts to offshore and coastal marine zones starting Friday and lasting through the weekend. Rapidly changing conditions are expected this weekend, especially across waters exposed to the Potential Tropical Cyclone One-C winds and swells.
Surf along south and west facing shores will continue to remain elevated as a new long-period south swell fills in tonight and peaks on Thursday. A High Surf Advisory (HSA) has been issued for south facing shores. This south swell energy will then slowly fade into Saturday and may linger at advisory thresholds into Friday. Another small reinforcement is expected late Sunday into Monday out of the south.
Surf along east facing shores will continue to remain moderate and choppy due to continued moderate to locally breezy trade winds. Swells from Potential Tropical Cyclone One-C could begin arriving as early as Friday, but the main energy from the Potential Tropical Cyclone will likely arrive this weekend and should produce surf heights exceeding warning levels along east facing shores. Based on the current forecast from the National Hurricane Center, dangerous surf conditions are expected around Maui and the Big Island on Saturday and around Oahu and Kauai Saturday night into Sunday.
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-Molokai West-Niihau-South Haleakala-South Maui/Upcountry-Waianae Coast.
Small Craft Advisory until 6 PM HST Thursday for Alenuihaha Channel-Big Island Leeward Waters-Big Island Southeast Waters- Maalaea Bay-Pailolo Channel.
