Flash flood warning issued for northern San Fernando Valley

The National Weather Service issued a flash flood warning for the San Fernando Valley Thursday afternoon. 

The advisory will last for at least a couple of hours until at least 6:00 p.m. Meteorologists said it will affect roughly 227,000 people near Panorama City, San Fernando, Sylmar and the surrounding neighborhoods in the northern valley. 

The NWS issues flash flood warnings when flash floods are imminent or already occurring in an area. Meteorologists urged residents to avoid walking or driving through flooded areas.