Freezing rain and sleet climatology of the southeastern USA

The Southeast USA averages 1.6 freezing rain and sleet events per year, ranging from 0 in southern Florida to over 5 in highland Virginia. Event frequencies and durations show 2 general trends: 1) a mountain-coastal decrease, and 2) a north-south decrease. Differences between freezing rain and sleet are evident in the upper air analysis: freezing rain events have higher 850 mb temperatures and lower surface temperatures. Freezing rain and sleet thickness differences show more variation for the 850 to 700 mb layer and less variation for the 1000 to 850 mb layer. Average 1000 to 500 mb thicknesses for freezing rain and sleet are both above and below the traditional 540 dam thickness. The ratio of freezing rain to sleet is consistently 2.0 or 2.5 freezing rain hours to 1.0 sleet hour in the upland stations, but is as low as 0.5 to 1.0 along the coast. -from Authors