Flash flooding possible on Kaua‘i & Ni‘ihau as much rain expected Sunday night

A flood watch is now in effect on Kaua‘i and elsewhere in the Hawaiian Islands.

Flash flooding caused by excessive rainfall is possible through late Sunday night according to the National Weather Service.

The agency issued the flood watch on the islands of Kaua‘i, O‘ahu, Maui, Moloka‘i, Lānaʻi, Kahoʻolawe and Ni‘ihau.

Flood-prone roads and other low-lying areas may be closed due to elevated runoff and overflowing streams. Urban areas may receive more significant flooding and property damage due to rapid runoff.

A trough developing near O‘ahu will merge with a front overnight and move slowly eastward, according to the weather service.

An upper level trough will trigger heavy showers and thunderstorms along the trough, bringing the threat for flash flooding, especially over windward areas. The flood threat will decrease during the day on Monday.

“You should monitor later forecasts and be prepared to take action should flash flood warnings be issued,” a weather service alert stated.