Hawaii's island chain is experiencing a weather roller coaster, with forecasts predicting a mix of moderate to heavy rainfall, and the possibility of isolated thunderstorms, particularly affecting the eastern end of the state. The National Weather Service (NWS) in Honolulu has noted that light to moderate trade winds should maintain through this evening, promising a bit of a respite from the more gusty conditions Hawaiians know all too well.
The weather pattern is in part thanks to a dissipating stationary front just north of the state, which, according to NWS, has been keeping the local pressure gradient relatively weak. To make conditions more complex, a plume of deeper tropical moisture is shifting northwestward across the islands, bringing increased showers that, due to a light trade wind, have the potential to seriously to cause nuisance type flooding. As for thunderstorms, they're on the menu, especially as an upper level shortwave trough digs in from the north later today, increasing the atmospheric instability.
Explaining the potential outcomes of these weather ingredients in play, NWS detailed, "With all of these ingredients in play, any slow-moving heavy showers or thunderstorms will have the potential to cause nuisance type flooding on any of the islands today." Islanders can expect these patterns to linger into tomorrow, though trades are anticipated to pick up slightly, bringing the familiar wet trade wind pattern that focuses showers over windward areas. While the sea breezes and their resulting showers are expected to occur, an influx of high clouds may temper the heating and subsequent sea breeze development.
In aviation terms, the weekend will be marked by ongoing light to moderate trades, with the western half of the state seeing sea breezes that could lead to isolated showers and low clouds over Oahu and Kauai. "Within any SHRA/RA/TSRA periods of IFR/MVFR conds are possible. VFR should prevail otherwise," the NWS alerts. An AIRMET Sierra for mountain obscuration is in effect for the windward Big Island and Maui, probably needed through the weekend.
As for those taking to the sea, the frontal system north of the islands maintains moderate winds. Despite this, mariners should prepare for the chance of thunderstorms, which could persist in offshore waters into midweek. Surf conditions on east facing shores are to decline by tonight, but the presence of Tropical Cyclone Kristy continues to elevate seas and could see surf advisory thresholds reached by midweek. Visitors and residents along the coast should pay heed to the High Surf Advisory in effect until this evening for various spots across the islands including Olomana and the windward side of both Maui and Kauai. For detailed weather updates and advisories, visit NWS Honolulu.
