Oahu faces flood watch as heavy tropical rain arrives Tuesday

A flood watch is currently in effect for all islands, signaling the arrival of deep tropical moisture that will bring heavy rain and thunderstorms to Hawaii starting Tuesday. The heaviest rainfall is expected to hit Tuesday night and continue through Wednesday night, with Oahu and Maui County likely to record the highest totals.

Conditions are stable tonight with light trade winds, but increasing high clouds mark the approach of the storm system. Showers will intensify Tuesday, particularly later in the day, as moisture moves in from the southwest. Slow-moving showers during this period could produce very heavy rain in a short time, creating dangerous flash-flooding conditions. Strong thunderstorms and locally gusty, potentially damaging winds are also possible Wednesday.

The storm system will gradually ease heading into Thursday and Friday, though humid weather and pockets of heavy showers may linger. Trade winds could briefly return Saturday, followed by stronger northeast winds Sunday. On the Big Island, howling westerly winds are already picking up on the high summits and could reach intense warning levels by mid-week, making high-altitude travel not recommended. Kauai will experience increasing gray skies and soaking tropical showers that could last through Thursday.

Chief meteorologist Jennifer Robbins and the weather team at Hawaii News Now are tracking the system closely. Residents should monitor updates via the HNN Weather app on the Apple App Store or Google Play. Although the heaviest rain may not arrive until Tuesday night, conditions can change quickly. The forecast indicates a shift from unstable, wet weather to drier conditions by the weekend as trade winds attempt to reestablish themselves over the islands.