Objective Classification of Tornadic and Nontornadic Severe Weather Outbreaks Mercer, Andrew E. ; Shafer, Chad M. ; Doswell, Charles A. ; Leslie, Lance M. ; Richman, Michael B. Abstract Publication: Monthly Weather Review Pub Date: 2009 DOI: 10.1175/2009MWR2897.1 Bibcode: 2009MWRv..137.4355M