All Hawaiian islands are under a flood watch from Sunday evening until Tuesday afternoon, as a cold front brings the possibility of heavy rains, starting with Kauai.

“As the front moves over the islands, conditions will become increasingly favorable for the development of heavy rain that will be conducive to flash flooding,” the National Weather Service in Honolulu said Saturday night. “The heaviest rain is expected initially for Kauai beginning late Sunday, then spreading down the island chain to the remaining islands on Monday. A few thunderstorms will be possible as well.”

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

Forecasters said “another system will quickly follow during the second half of next week, continuing the threat for unsettled weather into early next weekend.“