Cold Water and High Ice Cover on Great Lakes in Spring 2014

Very cold temperatures across much of North America caused by the recent anomalous meridional upper air flow—commonly referred to in the public media as a polar vortex (for details, see Blackmon et al. [1977] and National Climatic Data Center, State of the climate: Synoptic discussion for January 2014, http://www.ncdc.noaa.gov/sotc/synoptic/2014/1 )—have contributed to extreme hydrologic conditions on the Great Lakes. The Great Lakes are the largest system of lakes and the largest surface of freshwater on Earth—Lake Superior alone is the single largest lake by surface area.