Flood watch issued as potential tropical cyclone likely to bring heavy rain

While its track is uncertain, a potential tropical cyclone is expected to bring heavy rain to the eastern end of the state throughout the coming days, triggering National Weather Service forecasters in Honolulu to issue a flood watch from the afternoon of Sept. 23 through the afternoon of Sept. 26 for the Big Island.

Flash flooding caused by excessive rainfall is possible. Flood-prone roads and other low-lying areas could be closed because of elevated runoff and overflowing streams. Urban areas also might might receive more significant flooding and property damage because of rapid runoff.

Heavy rain on the north side of a developing tropical system — the future Nolo — should develop Wednesday afternoon. Windward and southeast Big Island and windward Maui are the most likely to experience heavy rain; however, other islands in Maui County are at risk as well.

Very high rainfall rates, which can cause flash flooding, are possible within the entire watch area.

The public should monitor later forecasts and be prepared to take action should flash flood warnings be issued.