The deadly EF5 tornado that hit Moore, Oklahoma on May 20 was unique in several ways. Not only was it one of the strongest twisters ever recorded, but forecasters were able to issue a tornado warning 36 minutes in advance, saving lives. Playing a part in that forecast was a Cray supercomputer at the National Institute for Computational Sciences (NICS). NICS' new Cray XC30 supercomputer, known as Darter, was used by researchers at the Center for Analysis and Prediction of Storms (CAPS) at the University of Oklahoma from April 22 through June 7, right in the heart of the spring storm season. The weather prediction work was done as part of the spring Hazardous Weather Testbed (HWT) experiment sponsored by the National Oceanic and Atmospheric Administration (NOAA). To read further, please visit http://www.hpcwire.com/hpcwire/2013-08-12/cray_supercomputer_gave_forecasters_an_edge_in_tornado_prediction.html.