Tropical moisture continues to hit the Big Island with heavy rain, triggering a flash flood warning and a flood watch for both Maui and Hawaii Island. Showers are expected state-wide on Tuesday. Tonight and Tomorrow: Heavy rain and thunderstorms are expected for Maui and the Big Island. This rain will spread to Oahu and Kauai on Tuesday. Flash flooding is a major concern, especially for the Big Island. Later this Week: A cold front will bring wet, windy weather to the islands. Be prepared for rain showers and gusty winds.