A weather system is expected to bring a period of unsettled, wet conditions to parts of Hawaii, including thunderstorms and potential localized flooding in areas such as Niihau, Kauai, and Oahu. According to the National Weather Service in Honolulu, a cold front accompanied by a prefrontal cloud band will bring cloudy and rainy weather starting this evening and continuing through Monday, primarily affecting the western Hawaiian Islands.
The NWS's satellite data this morning showed the front approaching from about 600 miles northwest of Kauai, bringing showers to the region as a result, shower activity is predicted to intensify on Kauai throughout the day with bands of showers likely to extend to the eastern and southeastern slopes of the Big Island. The prefrontal convergence near Kauai, in conjunction with convergence cloud band from the approaching cold front, are likely to heighten shower activities over the western islands, with a stalling front expected to dissipate near Oahu by tomorrow evening.
A shift in the weather is forecast to occur by Tuesday, as stable easterly trade winds are predicted to return, ushering in periods of typical windward and mountain showers, particularly during the overnight to early morning hours. Later in the week, from Wednesday night through the weekend, an upper-level ridge is set to bring drier and more stable conditions to the entire state, with another frontal system potentially influencing the wind patterns again by next weekend.
For aviation, the approach of clouds and showers could lead to periods of marginal VFR or worse conditions, mostly for Kauai and Oahu, the expected increase in wet weather causing AIRMET Sierra alerts for mountain obscuration in these areas, although forecasts suggest a temporary improvement throughout the morning. The marine outlook includes moderate southeast to southerly winds associated with the front, along with a notable northwest swell that could elevate surf to High Surf Advisory levels by tomorrow, potentially prompting the need for Small Craft Advisory warnings due to the swell's peak from tomorrow night into Tuesday.
While no watches, warnings, or advisories have been announced at this time, it is prudent for residents and visitors in the affected areas to stay informed of the latest weather developments and be prepared for the changing conditions forecasted for the coming days.
