On November 17, 2013, the National Weather Service/Storm Prediction Center received over 600 preliminary (not yet verified) reports of severe weather (tornadoes, high winds, or large hail) from several Midwestern and northern Appalachian states, stretching from the Mississippi River to New Jersey. As of 9 a.m. on November 18, the Center was indicating that it had received 81 preliminary reports of tornadoes, concentrated in Illinois, Indiana, and Kentucky (please note that a given tornado may result in more than one report).
For the National Weather Service/Storm Prediction Center’s map and list of preliminary reports for November 17, 2013, go to this link:
http://www.spc.noaa.gov/climo/reports/131117_rpts.html. The map is shown below. At the Center’s site, one can also access the archive of maps and report lists for previous days going back several years.