The National Weather Service (NWS) in Honolulu has issued a series of advisories and forecasts as Hawaii is set to experience a mix of weather conditions in the coming week, focusing on persistent trade winds, increased moisture leading to showery weather, and marine impacts from a combination of wind and swell. According to the NWS Honolulu weather forecast, high-pressure systems to the northwest and north will drive trade winds across the islands, with moisture from an old front affecting Kauai through tomorrow before shifting southward and spreading showery conditions across other islands later in the week.
The trade winds, which have been breezy to windy today, are expected to moderate somewhat tomorrow before ramping up again later in the week. The strong high-pressure system northwest of the state, which will peak at around 1035 mb today, in combination with inversion heights lowering to around 6,000 feet this afternoon over the eastern end of the state, is likely to bring advisory-level winds to some of the windier areas of Maui County and the Big Island, resulting in a Wind Advisory for parts of Maui County and the Big Island through this evening. Meanwhile, the NWS anticipates periods of showery weather, mainly in windward areas, which may spread leeward at times due to the trade winds.
In other aviation-related concerns, breezy to locally windy trades are expected to blow through for the next 24 hours, resulting in low clouds and passing showers for windward and mountain areas, while periods of MVFR or brief IFR conditions are anticipated amid the showers, especially on windward Kauai. AIRMET advisories have been issued for mountain obscuration across windward portions of Kauai and low-level turbulence downwind due to the trades across the state.
The marine forecast from the NWS highlights rough conditions due to fresh to strong trade winds, rough seas, and an ongoing long-period north swell that has prompted the issuance of a Small Craft Advisory across all Hawaiian waters, potentially through tomorrow. Trade winds are forecast to decrease slightly late tomorrow and Tuesday before rebuilding by Wednesday. Similarly, seas are expected to drop below advisory levels as the large weekend swell subsides, but moderate to heavy harbor surges are expected to continue in north-facing harbors. Meanwhile, the north swell is creating warning-level surf across most north- and east-facing shores and advisory-level surf on many western coastlines. A decline in surf height is expected for mid-week, with another swell possibly impacting the shores later in the week.
The islands are currently under a High Surf Warning until this evening for various areas, including Niihau, Oahu's North Shore, and parts of Maui and the Big Island, while west-facing coastlines of Kauai and other regions remain under a High Surf Advisory. The intense power of nature is on display, as the NWS also notes that overlapping small south swells are expected to boost south shore surf from tomorrow through Thursday before settling down. Amid these varying conditions, residents and visitors alike are advised to be cautious and stay informed of the latest weather updates.
