Polar Vortex | The Migration captures a rare weather phenomena involving plunging artic temperatures and a wildlife food supply sealed by a solid cap of ice across the Great Lakes. Scientists were buzzing when the first trace of open water triggered unusual migratory patterns. The Oswego Harlequin was a rare capture of an elusive migratory bird driven off course by the same survival instinct as the others. Sudden spikes in sub-zero (F) temperature released ice sheets and fast flowing water that would freeze back up in a dangerous ebb and flow. When waters finally opened the survivors had endured the grips of an extreme polar vortex.