Hawaii Unknown Hydrologic Outlook | Effective 08/12/2026 18:22

ESFHFO The latest forecast for Potential Tropical Cyclone One-C takes the system over the state as a strong tropical storm. While One-C is expected to move steadily west-northwest as it passes through the island chain, abundant moisture drawn into the circulation will bring the potential for very heavy rainfall and flash flooding from late Friday into the weekend across the state. While the details on the timing and rainfall amounts will highly depend on the eventual track of the tropical cyclone, we could see widespread rainfall of 5 to 10 inches. Locally higher amounts will be possible, especially over the windward areas of Maui and the Big Island. Keep up to date with the latest forecast information online at weather.gov/hawaii, through local media, social media, or NOAA Weather Radio broadcasts. An updated outlook will be issued by 5 PM HST Thursday unless superseded by a Flood Watch.