A Climatology of Freezing Rain in the Great Lakes Region of North America

Abstract

Abstract A 15-yr climatology of freezing rain surrounding the Great Lakes region of North America has been constructed using data from rawinsondes, surface stations, and gridded reanalyses from the National Centers for Environmental Prediction. This climatology reveals that there is a general increase in the freezing-rain frequency from west to east; however, the distribution shows large spatial and temporal variability. Most freezing-rain events are short lived and occur near sunrise between the months of December and March. Continuous freezing rain typically lasts less than 1 h, with 7% of events lasting longer than 5 h. Most freezing rain is associated with extratropical cyclones, occurring northeast of the cyclone center in the presence of midlevel upward vertical motion, and air that is nearly saturated at low and midlevels, subfreezing near the surface, and warm (>0°C) at low levels (≈850 hPa). The location of the mean extratropical cyclone track during freezing-rain events in the Great Lakes region...