a 12" wide board of northern red oak will vary 7/32 " in width (shrinkage in winter, expansion in summer) based on the variation in ambient humidity as the flooring may go from 10% moisture in summer to 4% in winter. In narrow flooring this differential gets distributed among four or five separate boards (joints), but wide flooring concentrates the gap at one point. Your wide floor boards need plenty of time to acclimate. Install when they are at the same moisture content as the subfloor. This must be determined with a digital meter of known accuracy. If the flooring is manufactured by a reputable maker, it will come with instructions, which should be followed. If you are buying wood directly from the mill, you will have to rely on the knowledge of the installer, so pick a good one. You may have to screw the boards down and plug the holes. IMO, that effect does not look great unless done with long lengths of boards.
Casey