A classical cold air damming (CAD) event occurred across the Piedmont of Virginia and the Carolinas on 07-09 December 2013. The event resulted in some freezing rain across the northern and northwestern Piedmont of North Carolina along with other wintry precipitation further north into Virginia and across the higher elevations of North Carolina. In addition to the wintry precipitation, temperatures were well below normal during the period and failed to climb out of the 30s or lower 40s during much of the time with persistent low clouds, fog and drizzle.
The image below is an adapted image of the wind profiler at Clayton, NC (located about 30 miles or 50 kilometers southeast of KRDU) which is on the eastern edge of the climatologically favored CAD region. The profiler is operated by the NC Department of Environment and Natural Resources with the imagery provided by the NOAA ESRL HMT-SEPS project. The top portion of the image shows the profiler sampled wind speed and direction with height on the vertical axis. The horizontal axis is the time in hours (UTC) from right to left that begins at 06 UTC on 12/07 on the right and runs through 18 UTC on 12/09. The cold air damming region can be seen in the surface based layer with a northeast to northerly wind (not just the cool colors) that begins at 11 UTC on 12/7 and extends through around 08 UTC on 12/9. The depth of the CAD air mass increases rapidly on 12/7 and peaks close to 00 UTC on 12/8 and then begins to decreases with time and becomes rather shallow for during the last 12 hours. The WPC surface analysis from every 12 hours is shown below the wind profiler plot with a red dot and line noting when the surface analysis is valid.