Strong thunderstorms and heavy rain are probably east of the Cooper River (that's Mount Pleasant, Cainhoy, etc.) through at least 11 a.m.
The National Weather Service says:
At 9:12 a.m. EDT...National Weather Service doppler radar indicated a line of strong thunderstorms capable of producing gusty winds of 30 to 40 mph. these storms were located along a line extending from 8 miles northeast of Whitehall Terrace to Whitehall Terrace...or along a line extending from 14 miles southwest of McClellanville to 10 miles northeast of Charleston...moving west at 8 mph.
Areas in and around Cainhoy...Daniel Island...Wando...Mount Pleasant and Isle of Palms will be impacted through 10 am EDT.
This thunderstorm is capable of producing very heavy rain...which may flood ditches and low-lying areas. avoid flood prone areas and do not drive into places where water covers the road. Doppler radar estimates that over 1.5 inches has fallen with these storms...and an additional 1 inch is likely through 10 am EDT.
More thunderstorms are possible throughout the region after 2 p.m. today.