Friday, December 6, 2013
NWS Summary of November 17 Tornado Outbreak
larger version of image), indicating the thunderstorm had developed rotation (a mesocyclone) on its SW side. Rotation does not guarantee that a tornado will form, but it it a precursor - and this one did spawn a tornado. Evaluation of the aftermath indicated the intensity reached EF-4 as it moved through Washington, IL (aerial photos). Amazingly there were only 2 deaths in the city of over 15,000. Cell phone warnings alerted many who were in church. CLICK HERE to see/read other storm summary resources posted by the National Weather Service. This Wikipedia page is another good source. Also, check out this RADAR PowerPoint presentation that I have posted.