Robbins and Cortinas (1996) showed that freezing rain over the contiguous United States is a rare event that is highly variable in time and space. These events were most frequent in areas north and east of surface low pressure systems, where strong upward vertical motion, strong warm air advection below 700 hPa, and subfreezing surface air all combined to produce an environment conducive to freezing rain. Over the Great Lakes, many of these general freezing rain characteristics also are present and freezing rain occurs throughout the winter season in this region as well. This study will use a database of hourly surface observations and rawinsonde data from 1976-1989 to summarize the spatial and temporal distributions of freezing rain reports over the Great Lakes, including Canadian locations. Results from this study will provide forecasters with information about the occurrence of freezing rain, and provide a baseline for future studies on how global change may affect the climatology of hazardous winter weather events.
Robbins, C., and J. V. Cortinas Jr., 1996: A climatology of freezing rain in the contiguous United States: Preliminary results. Preprints, 15th Conference on Weather Analysis and Forecasting, Amer. Meteor. Soc., Norfolk, VA, 124-126.