Honolulu gets one more mostly sunny stretch Wednesday before the weather takes a serious turn. Highs should reach about 86 degrees, but showers arrive after 2 p.m. and the forecast becomes much wetter Wednesday night, with thunderstorms and heavy rain possible across Oahu.
The National Weather Service in Honolulu has issued a Flood Watch for Oahu from Wednesday evening through Thursday afternoon, with the watch set to continue until 6 p.m. Thursday. Forecasters warn that intense rain could trigger rapid runoff, overflowing streams, flooded roads and urban flooding, especially in low-lying and flood-prone areas.
Heavy Rain Arrives Wednesday Night
Wednesday night into Thursday brings a 60% to 70% chance of rain, with 1 to 2 inches possible in some areas during the midweek period. Some storms could produce especially heavy downpours, while winds become south-southeast by evening.
Thursday is expected to remain wet, with more thunderstorms and a 60% to 70% chance of rain. The forecast allows for 1 to 2 inches in some areas during the midweek period, with heavy showers possibly continuing Thursday night.
Residents should keep an eye on later alerts and avoid driving through water covering a roadway. The flood threat is tied not just to total rainfall but to the possibility of repeated heavy showers over the same areas, which can overwhelm drainage and push streams out of their banks.
Friday Starts The Slow Improvement
Friday remains unsettled, with scattered rain showers, partly sunny breaks and a high near 87 degrees. Another 1 to 2 inches of rain is possible before conditions begin to ease.
The new Flood Watch is a substantive escalation from Hoodline's earlier forecast, which described a stormier midweek pattern but did not include a watch. The National Weather Service alert says residents should monitor later forecasts and be ready to act if Flash Flood Warnings are issued.
Weekend Looks Calmer And Drier
Showers should become more scattered Friday night, with mostly sunny periods returning Saturday and Sunday. Isolated showers carry about a 30% chance each afternoon.
Columbus Day on Monday should bring isolated showers, with a high near 84 degrees. Light to moderate trade winds are expected to return for the weekend, offering a quieter finish after Thursday's potentially dangerous rain.
