A flash flood watch has been issued for Oahu and Maui County through tonight. 

National Weather Service forecasters said a slow-moving front combined with a “vigorous upper trough” is expected to bring heavy rains as the system moves east over the islands.

The front is expected to stall and gradually dissipate near Maui on Monday, the weather service said.

Radar showed moderate to heavy rains moving over Lanai and Molokai at 2:36 p.m., prompting a flood advisory. The advisories for Molokai and Lanai have been cancelled.

Residents are urged to stay away from streams, drainage ditches and low-lying areas prone to flooding. Driving can also be hazardous because of reduced visibility and water on the roads.

A flash flood watch means conditions may develop that lead to flash flooding.