To be honest, I am not sure how this topic got to be featured, but I am very grateful to AmericanWX for the tremendous illustration of an EML that introduces the topic. My goal was to have a discussion that survived particular events, and the discussion exceeded my wildest hopes. Lots of very smart people kicked in lots of valuable information. One of the most valuable bits was the link to the Storms Prediction Centers experimental page, which is an amazing wonderland of graphs and maps. See http://www.spc.noaa.gov/exper/mesoanalysis/new/viewsector.php?sector=19#, for example. Perhaps some readers could shed light on the resources here?
The role of EML's in tornadoes is still a puzzle to me. Notice that while the late April outbreak in the south seemed to have a lot to do with dry lines and eml's, the recent mother's day outbreak did not, at least so far as I could see. I would love to see that paradox discussed.
My thanks to everybody who participated .. and to any others who will pitch in.
N