In this video excerpt from NOVA: “Deadliest Tornadoes,” examine how the climate phenomenon of La Niña may help set up conditions conducive to large tornado outbreaks. Thermal images show a region of unusually cold sea-surface temperatures in the eastern Pacific Ocean, off the coast of Peru. This deviation from normal sea-surface temperatures, called La Niña, impacts ocean processes and global weather. Scientist Roger Pielke, Sr. explains how during a La Niña event, the combination of a strong jet stream and moist air in the southeastern United States may provide prime conditions for a particularly dangerous tornado season in 2011. (Pielke was correct, as an unusually high number of tornadoes were reported across the United States in 2011.)
This video is available in both English and Spanish audio, along with corresponding closed captions.
Visit the program page here.