Trade winds will become light enough to allow for afternoon sea breezes, with an increasing potential for spotty showers, some of them heavy, from Kauai to Maui. There’s a deeper pool of moisture for the Big Island, which is under a flash flood watch through Saturday afternoon. Be prepared for the possibility of more heavy showers and thunderstorms.
The unsettled weather conditions will be the result of an upper level disturbance approaching from the northwest. That will bolster a mid-level to low-level trough already in place over the islands (the one that’s been firing up the wet weather over the Big Island during the past few days). The unstable conditions will persist into Saturday.
Trade winds should build back in with more stable conditions on Sunday, but there could still be more windward showers riding in on the strengthening trade winds. Longer term, there’s another tropical disturbance about 1,000 miles southeast of the Big Island that could brush the state with increased rainfall Tuesday through Thursday.
At the beach, an increasing south swell will bring waves in the 8-12 foot range Saturday, and this swell will likely hold pretty much all weekend. A High Surf Advisory will take effect at 6 p.m. Friday through 6 p.m. Monday for all south-facing shores. There’s also a boost in wave heights for north shores, but below advisory levels.