A cold front is moving across the Hawaiian Islands today, passing Kauai and Oahu this morning, Maui County this afternoon, and the Big Island this evening, bringing breezy northerly winds with cooler and drier conditions behind it. Another system is expected Wednesday night into Thursday, with gusty southerly winds developing Wednesday afternoon and the outlook noting, "Expect another round of moderate to heavy showers and even stronger winds associated with this second frontal passage," according to the National Weather Service.
By the weekend, a noticeable cooldown is expected as trade winds help maintain drier weather across the state. Aviation impacts include prevailing MVFR conditions with brief IFR possible in heavier showers, along with AIRMETs for mountain obscuration and turbulence due to strong winds, before conditions improve behind the front, as reported by the National Weather Service.
Marine conditions across Hawaii are hazardous as a front moves down the island chain and combines with a large, long-period northwest swell, producing warning-level surf along exposed shores. Marine advisories state, “A Small Craft Advisory was issued for most coastal waters exposed to the large northwest swell and increasing winds.” A High Surf Warning remains in effect until Tuesday evening for areas including Niihau, Kauai Leeward, and the Oahu North Shore, with Small Craft Advisories covering many waters from Kauai Northwest to Big Island Windward zones. Another northwest swell is forecast to arrive by Thursday, which could bring another period of high surf and rough marine conditions, as stated by the National Weather Service.
