Most of the time you might have to visit the websites of the National Weather Service area where the tornado occurred, following their survey of its track, to find out the rating.  That can definitely get cumbersome, and not all offices do this for all weaker tornadoes.  Sometimes they will also go back and add it to the text of the storm report, but that's unfortunately not always the case.  At some point the tornado ratings do get to SPC, but I'm not sure if there is a place to find that data; I have not yet found one.  Here's an example (from April 4 this month) of EF-ratings that have been added to many, but not all, of the tornado reports if you look at the "Comments" column: http://www.spc.noaa.gov/climo/reports/110404_rpts.html.  Even some from last year haven't been added.  One comment about basing everything on major events (EF2+) though - even if you were to do that, I think past polygons would have to keep all tornado reports in the scoring because the polygons themselves might have been created differently if the forecaster knew that only the stronger tornadoes would be counted.

Question about the density factor - how do you think it might be used in the scoring?  And does it only count the events that fell in the polygon, or does it count those outside it as well (maybe you answered this that it counts those outside it within the buffer given partial credit down to 0 at the blue line)?  I've look at examples such as yours and my polygons for May 7 (and same time) last year and try to figure out which would get the higher score if the percentage factors are replaced by density, since your outlook polygon, which didn't include the one single report, has a higher density (albeit only slightly) than mine, which did include it.

I have another qualm about the density factor - well I guess even the way things are right now.  What if you think there are two areas of possible tornado maximum chances (caused by the same system) with not much of a chance between, say one in western Ohio and another in northern Alabama (things like this happen, such as in the big outbreak I was living in northwest Ohio for on November 10, 2002 - http://www.spc.noaa.gov/climo/reports/021110_rpts.html - but say this isn't an outbreak).  Because you can only draw one polygon, you draw one to encompass the entire area between northwest Ohio and Montgomery.  That's a fairly large polygon, but you might not be expecting a large number of tornadoes in that area, just a few in northwest or west central Ohio and a few in northern Alabama.  They aren't far enough apart to fall under your proposed distance rule (and in fact they could be caused by the same system as in that 11/10/02 case).  Do you draw a large polygon and risk a small density score?  Do you draw a smaller polygon around one of the two areas and risk a large dst missed score?  Or maybe you draw polygons around the two areas connected by a very narrow sliver between the two such that it is one polygon with not too large a density score (but that would increase the negative perimeter score)?  This kind of situation is not limited to the proposed density score, it's an issue right now as well with the area and perimeter scores.

I have another suggestion - how hard would it be to include the year in the dates for each outlook?

One more thing.  My browser remembered my password for this site for well over a year, and today it wasn't there anymore.  For the life of me I couldn't get it right, apparently, so I created a new user name, cumulonimbus, as I really wanted to get an outlook out for Tuesday (I would have liked to do it a day ago but was too busy unfortunately).  Is there any way to put this new outlook under my nje310 name and secretly get me my password?  haha!