The CIMSS Probability Severe Model indicated low probability for severe storms 5-10% for a fast moving line of storms over eastern Michigan (northern part of line moving 50-60 mph) at 1928 UTC on May 13.  It seems to be a good idea to include DCAPE as a displayable variable in addition to MUCAPE, EBShear, MESH, Vertical Growth Rate, and Glaciation Rate and use this variable for calculating SVR PROBs.  The low probabilities are likely due to MESH values well below 1 inch (closer to 0.25 to 0.50 inch) as well as EB Shear generally 20-25 kt.

Michael Scotten