Honolulu residents are expected to experience increasing rain as a cold front moves across the state. The forecast indicates a pattern change with moderate south to southeast winds starting later today and continuing through the end of the week. Drier conditions are anticipated by the weekend as a surface ridge shifts northward. However, another weakening cold front may bring additional precipitation early next week, according to the National Weather Service in Honolulu.
The deep-layer ridging has kept conditions mostly dry and stable, with a strong subsidence inversion limiting showers to windward coastal areas. As the first cold front approaches, the NWS states that "increasing moisture and lift ahead of this boundary will enhance rainfall chances, particularly across leeward slopes and mountain areas in the western portion of the state." However, rainfall amounts are expected to be minimal, as the front is likely to stall north of Kauai.
In aviation news, pilots can anticipate light to moderate southeast to south winds as the front approaches. Winds are predicted to significantly veer to the south to southwest for areas over Kauai and Oahu. While isolated marginal VFR conditions are possible, VFR conditions should largely prevail. The National Weather Service has also indicated that no AIRMETs are in effect, and none are expected to be issued in the near term.
For those on Hawaiian waters, the NWS anticipates a large northwest swell to peak today and subside tonight. As a result, the High Surf Advisory has been upgraded to a High Surf Warning for most north and west-facing shores until 6 p.m. HST this evening, due to swell heights surpassing initial forecasts. A Small Craft Advisory remains in effect, extended "to account for hazardous seas across northwest waters exposed to the swell," states the NWS forecast. An even larger swell is projected to rapidly build late Thursday into Friday, potentially leading to High Surf Warning conditions once again.
The High Surf Warning is in effect until 6 p.m. HST for areas including Niihau, Kauai's leeward and north shores, and the Waianae Coast. A High Surf Advisory will be in effect from noon today through early Thursday for the Kona and Kohala regions. A Small Craft Advisory is also in effect for several surrounding waters around Kauai, Oahu, and Maui. Full details on all advisories, including affected shore regions, are available on the National Weather Service website.
