HONOLULU (KHON2) - For tonight, hi-res guidance, as well as the GFS, are hinting at the possibility of a surge of trade winds moving across the islands from north to south. Meanwhile, ample moisture will remain in place, and will be further enhanced as an upper level trough deepens into a low and moves closer to the state. Atmospheric instability will increase as this upper level feature moves closer, and will maintain the possibility for deeper convection and isolated thunderstorms. With all of these ingredients in play, any slow-moving heavy showers or thunderstorms will continue to produce flooding concerns. Isolated thunderstorms have also been added statewide for tonight through Sunday based on the latest guidance. On Sunday, trades will become locally breezy as the front north of the islands dissipates and ridging begins to build. The upper level low will move more directly overhead, providing increasingly unstable conditions aloft. With plenty of low to mid-level moisture still streaming across the state, it won't take much to kick off moderate to locally heavy showers over already saturated ground. With the strengthening trades, showers will likely transition to focus mainly over windward areas. However, showers will also still form in the more sheltered leeward areas, particularly over the Kona slopes of the Big Island where locally heavy rain has been added to the forecast again for Sunday afternoon. As the upper low pushes west of the area and surface ridging builds to the north, a breezy and increasingly stable trade wind flow is expected for much of next week, beginning on Monday. Pockets of moisture riding in on the trades will provide occasional brief upticks in windward showers throughout the week.