A low pressure system drifting in from Arizona prompted the National Weather Service to issue a flash flood warning for parts of eastern Riverside County Sunday.

The warning will be in place through 6:45 p.m. for Riverside County desert areas, including Chiriaco Summit, Box Canyon Road and the North Shore area near the Salton Sea, according to the NWS.

Forecasters said thunderstorms producing heavy rain were spotted across the warned area and had already dropped between a half inch and two inches of rain.

A significant weather warning was also issued through 3 p.m. by the NWS for the same area due to winds that could reach 40 mph and frequent cloud-to-ground lightening associated with the storms.

“Turn around, don’t drown when encountering flooded roads. Most flood deaths occur in vehicles,” the NWS warned.