CHARLESTON, S.C. (WCBD) – Heavy rain and thunderstorms could cause flooding in much of the Charleston metro on Monday. Widespread rainfall and thunderstorms – including excessive rainfall – will impact much of southeast South Carolina on Monday afternoon through the evening as a cold front moves through the area. DOWNLOAD IT: Grab the free Storm Team 2 weather app The National Weather Service (NWS) has issued a flood watch for Berkeley, Charleston, Colleton and Dorchester Counties through the evening. “Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations,” said NWS forecasters. “Flooding may occur in poor drainage and urban areas. Storm drains and ditches may become clogged with debris.” Storm Team 2 Interactive Radar Rainfall amounts are estimated from two to four inches with localized amounts up to six inches is possible. A risk for flash flooding will be greater around Monday afternoon’s high tide.