The National Weather Service in Honolulu has indicated a continuation of a dry, moderate to locally breezy trade wind pattern through tomorrow afternoon for the Hawaiian Islands. According to the NWS forecast, a weak disturbance is anticipated to increase shower activity across all islands over the weekend, particularly in windward and mountain areas, with the possibility of isolated thunderstorms hitting Kauai and Oahu from Saturday night through Sunday.
Current radar imagery captured minimal shower activity this morning, with the bulk of it being brief showers in windward and mountain regions. The calm-patterned stratocumulus clouds carried by easterly trade winds, are interspersed with bands of high-level cirrus clouds – which are expected to enhance the visual spectacle of sunrises and sunsets into the weekend. A ridge of high pressure situated far to the north of the islands is tasked with steering these moderate, occasionally gusty trade winds until tomorrow.
The decrease in wind speeds over the weekend correlates with the forecasted weakening of this high-pressure ridge due to a cold front moving through the Central Pacific basin. A prediction of stable conditions reducing rainfall chances accompanies this phenomenon through tomorrow afternoon, "Fairly strong subsidence (downward vertical motions) across the region will limit rainfall coverage through Friday afternoon," as described in the NWS forecast.
The presence of a low-level trough and an upper-level low converging on the islands is set to unsettle the stable conditions and amplify shower trends from tomorrow night into the weekend. "The development of any thunderstorms will highly depend on the strength of this developing upper low near the western islands this weekend," the NWS forecast clarified. Drier conditions are projected to make a return from Monday next week as these low-pressure systems diminish, and shift westward, away from the state. Concurrently, moderate trades are set to prevail, along with scattered night to early morning showers in windward and mountain areas.
Aviation forecasts confirm that the breezy easterly trade winds will persist through the current 24-hour TAF period, with occasional MVFR CIGS/VSBYS as showers move through. Airmen are thus cautioned to expect low-level turbulence over and near island terrain later today. In marine news, a Small Craft Advisory remains in place through early Saturday for waters surrounding Maui and the Big Island due to persistent moderate to strong trade winds. For surfers, the north shore will see minimal activity until a northwest swell is expected mid-week, while east shore levels are predicted to decline into next week. Small Craft Advisories will be in effect until 6 AM HST Saturday for select high-wind areas.
