Honolulu is bracing for a dynamic shift in weather, with forecasters from the National Weather Service predicting a range of conditions, including trade winds, isolated thunderstorms, and potential flooding from heavy rainfall. According to the latest forecast, residents can expect rainfall amounts between 2 and 4 inches in parts of the Big Island, although local officials have not reported any significant flooding so far.
The report suggests that a weak low-level boundary is enhancing showers and possibly isolated thunderstorms, particularly across the north and east slopes of Big Island, which could persist into the afternoon. This boundary is then expected to lift northwestward over the next couple of days. The Big Island last night was subject to heavy rainfall, but, as of early this morning, the Big Island officials reported no significant flooding situations.
Looking ahead, moderate to breezy trade winds will follow a shallow cold front moving through the Hawaiian islands from Monday into Tuesday. As this front passes, it's predicted that a wet weather pattern will establish across the state, with showers expected to favor the north and east slopes of each island as well as along the passing frontal cloud band. A shift to very wet weather with southerly kona winds could come into play by next week Thursday, which may lead to heavier rainfall and thunderstorms.
With regard to aviation interests, airmass instability coupled with daytime heating may lead to widespread afternoon convection, the NWS said. This specifically impacts areas over the eastern end of the state, where moderate to heavy showers have been lingering off the east coast of Big Island. An AIRMET Sierra warning has also been issued for mountain obscuration in the vicinity, although conditions are expected to improve by mid-morning before potentially developing again later in the day.
On the marine front, light to moderate winds will persist into the weekend, with periods of heavier breezes possible. For surfers, northerly swells are on the decline, but surf heights may approach advisory levels by mid-week if a potential gale develops to the north as predicted. South-facing shore surf, meanwhile, will hover around the seasonal average.
Fire weather concerns will be tempered as wind speeds should remain below critical thresholds until the middle of next week. However, with the forecast shift to southerly winds and heightened moisture levels projected for Thursday, widespread rainfall is expected to raise moisture content and diminish fire risks across all islands.
