Around Michigan & State Government Around Michigan & State Government Coverage from across Michigan and the state Capitol with the Michigan Public Radio Network and Interlochen Public Radio. Powerful 'Polar Vortex' Makes Rare Appearance In U.S. Published January 6, 2014 at 3:57 PM EST Listen • 4:13 Powerful 'Polar Vortex' Makes Rare Appearance In U.S. Listen • 4:13 Copyright 2014 NPR