The Hawaiian Islands are bracing for potential catastrophic flooding and mudslides as a re-strengthening tropical depression, expected to become Hurricane Nolo, approaches. The system, which originated in the Eastern Pacific on September 13 as Tropical Depression 15-E, has a 90% chance of reforming into at least a depression within 48 hours. Impacts are anticipated to begin this afternoon, primarily affecting Hawaii island and Maui County, with a flood watch issued for Hawaii island, Maui, Lanai, Molokai, and Kahoʻolawe lasting through Saturday afternoon.
Forecasts indicate rainfall totals could reach between 10 to 25 inches or more for the Big Island, and 3 to 12 inches for Maui, with other parts of the state experiencing 1 to 4 inches or less. Life-threatening, catastrophic flooding and mudslides are possible, especially in areas with steep terrain. Windward and southeast portions of the Big Island, along with windward Maui, are identified as the most vulnerable areas for heavy rain. Winds could also intensify, with gusts exceeding 50 mph, and potentially reaching hurricane force if the storm makes landfall. Swells generated by the storm are expected to impact the east and south-facing shores of the Big Island by Friday.
The exact path and strength of the system remain highly uncertain, with forecasters noting that "every solution you can imagine is on the table today." While current models largely show the system remaining south of the islands, some models, such as the ECMWF, depict it moving directly over the Big Island. Emergency officials are urging residents and visitors to prepare emergency kits, secure property, identify evacuation routes, and be ready for potential prolonged power outages. Hawaii County Mayor Kimo Alameda has been preparing the Kau District, focusing on clearing channels and basins, with Hawaii National Guard personnel already assisting in cleanup efforts from Hurricane Lala, which previously impacted the region. The Hawaii Emergency Management Agency advises clearing gutters, checking sump pumps, elevating valuables, and reviewing preparedness plans.
