Honolulu residents can expect to keep their umbrellas at hand with sporadic downpours forecasted as lingering effects of Tropical Storm Gilma and a trailing weakness from Tropical Storm Hector. According to the National Weather Service in Honolulu, although Gilma is projected to diminish into a depression today, increased rainfall remains on the agenda, potentially persisting into the weekend. Satellite data has provided a clear picture of the excessive moisture heading toward the Hawaiian Islands, currently visible on CIMSS MIMIC precipitable water satellite imagery.
Despite the weakening systems, the Big Island and Maui should prepare for the brunt of the wet conditions by Thursday night. Officials have also projected rainfall accumulation between one to three inches, urging residents to be wary of potential localized flooding. "A narrow swath of drier air and some weak subsidence ahead of Tropical Storm Gilma may briefly reduce the shower activity today," the National Weather Service Honolulu Forecast discussed, indicating a brief respite before showers pick up again, particularly in windward and mountain areas.
As for the residents anticipating a break in the muggy conditions, it may be a short reprieve. The remnants of Gilma, keeping to the east, are set to drive dewpoint temperatures up into the mid-seventies. The aftermath, in addition to diminishing winds, is anticipated to give rise to sultrier, stagnant air that will make the warmth feel more oppressive than usual. Gilma's remnants are on a track that, should it shift slightly southward, higher rainfall totals would be seen across the state, as per the National Weather Service.
Following on the heels of Gilma, Tropical Storm Hector has been downgraded to a remnant low, poised to introduce a slight increase in showers as it approaches Saturday night into Sunday, as mentioned by the National Weather Service. The potential for heavier rainfall will then shift toward Oahu and Kauai Friday night into the weekend. As the remnants of Hector begin circulating a diffuse moisture plume, the trade winds are expected to pick up again, ushering in hopes for some respite as moderate to fresh breezes promise to disperse some of the lingering humidity and cloud cover early next week.
While no watches or warnings are currently in place, the aviation sector will keep an eye on MVFR conditions due to increased shower activity, mainly during the night and early morning. Mariners are advised to anticipate moderate to fresh trade winds, experiencing minimal changes in intensity, though this could be revised should Gilma's path alter. Beachgoers might note a slow decline in surf on east-facing shores through the week, with surf along south-facing shores projected to continue to wane.
