Major Northwest Swell Triggers High Surf Warnings Across Hawaiian Islands

A significant northwest ocean swell generated hazardous surf conditions across the Hawaiian archipelago over the weekend, peaking on Sunday morning, November 30, 2025. The National Weather Service (NWS) in Honolulu issued High Surf Warnings for the north-facing shores of several islands, forecasting wave heights between 35 and 45 feet.

This event marks the initial major winter swell of the season, driven by powerful Pacific storms traversing the northern Pacific, a characteristic pattern for the winter period extending from November through April. Coastal areas faced a heightened risk of inundation as ocean water surged over beaches, potentially impacting essential infrastructure, including public roadways.

The NWS criteria for a High Surf Warning, which signals an "especially heightened threat to life and property within the surf zone," typically requires shore-breaking waves of 15 feet or greater. Forecasters maintained high confidence that north-facing shores on islands such as Kaua'i would experience warning-level surf reaching 40 to 50 feet, including occasional larger sets. The immense force of these waves underscores the inherent danger, as the impact of a five-foot wave is exponentially greater than that of a one-foot wave.

Navigating harbor entrances and channels became complicated due to the presence of powerful rip currents and longshore currents. For the Big Island, a separate High Surf Warning was anticipated for the west-facing shores, with dangerously large breaking waves projected to build to 15 to 20 feet, peaking late Saturday night into Sunday morning. This swell originated from a hurricane-force low in the Central Pacific, situated approximately 1,400 nautical miles northwest of Kaua'i, directing a large sea fetch toward Hawaii.

Ocean safety officials, in coordination with civil defense agencies, strongly urged the public to avoid all affected shorelines and strictly adhere to directives from lifeguards, citing the potential for serious injury or fatality. The NWS indicated that wave heights would begin a gradual recession through Monday, with surf levels expected to fall below advisory thresholds by early Tuesday morning in some locations. Visitors and residents were cautioned that even standing near the shoreline during such conditions presents a hazard due to the reach of large breaking waves.

Furthermore, the same swell event prompted a Small Craft Advisory for surrounding waters, effective from noon Saturday through Monday, signaling challenging conditions for maritime operations, particularly near harbor mouths. This substantial ocean event, defined by an extra-large, long-period northwest swell, highlights the dynamic and potentially perilous nature of Hawaii's winter ocean environment.