(BIVN) – The National Weather Service in Honolulu has issued a Flash Flood Watch for all Hawaiian Islands through Monday afternoon.

“A trough of low pressure will linger across the island chain today through Monday, while an upper level low moves overhead,” forecasters wrote in a early morning message. “This will produce very unstable conditions across the state, bringing the potential for periods of heavy rainfall and flash flooding.”

East Hawaiʻi experienced thunderstorms overnight, and heavy rain triggered a Flood Advisory for North Kohala.

“A Flash Flood Watch means that conditions are favorable for flash flooding,” the National Weather Service said. “Flash flooding is LIFE THREATENING. Do not cross fast flowing water in your vehicle or on foot.”

The Flash Flood Watch may eventually need to be extended in time for all or portions of the island chain, forecasters say.