A brilliant animation

Surface air temperature over North America – January, February, 2014

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The winter of 2013–14 in a nutshell 

Multiple surges of frigid air sweep across eastern North America during January–February 2014, as shown in this visualization from NCAR’s Computational & Information Systems Laboratory. 

The maps depict surface air temperatures, which are measured at a height of 2 meters (about 6 feet) above ground level. 

The flow of cold air into the eastern United States was facilitated by the upper-level “polar vortex,” not shown, which shifted from its average location near the Arctic into lower latitudes of eastern North America several times during the winter of 2013–14. 

These hour-by-hour images are based on data generated by the NOAA Climate Forecast System model and visualized using NCAR Command Language software. 

The model was updated with observed data every six hours. Click on the "Full screen" brackets icon at lower right in the video to enlarge