Analysis of freezing rain patterns in the South Central United States: 1979–2009

Freezing rain (FZRA) events are among the most hazardous winter weather phenomena in the United States. Ice storms can severely damage property, overhead power and communication lines, transportation routes, and the natural environment. As synoptic weather patterns shift over time in response to climate change and variations, it is possible that regional and seasonal FZRA patterns may be altered. Because individual FZRA events generally occur within a narrow band, regional patterns – and their evolution over time – are of great interest to industries, insurers, and society as a whole. Historically, there have not been an adequate number of weather stations to accurately determine regional-scale FZRA patterns. Additionally, many stations only report data once per day, and often specific-typed accumulated precipitation is not available. For this initial work, the National Centers for Environmental Prediction (NCEP) North American Regional Reanalysis (NARR) high resolution 32-kilometer gridded 3-hourly data set was utilized to examine FZRA trends for Arkansas and eastern Oklahoma, a region in the South Central U.S. that is subject to episodic FZRA events. Data was analyzed for the period 1979–2009 to assess trends, including the frequency, intensity, and duration of FZRA events as well as temporal and spatial distributions in this region. Gridded reanalysis data is compared with geographically corresponding relevant station observations for validation of the model data.