For a few minutes, there were light showers in downtown Savannah on St. Patrick’s Day. But they quickly gave way to a thundering parade. As grand marshal Michael Foran and others started their long stroll through the Historic District about 10:30 a.m., hordes of folks sporting just about every shade of green were packed onto the sidewalks to cheer them on. The noise of the crowds and parade participants heading downtown at 6 a.m.