Would argue that given the meso disco out, even though it's only 40% watch probability, that we get upgraded to a slight risk with the afternoon update.
I ran a history of all Excessive Heat Advisories through the iembot. I don't have the time to view the results, but here's a KML file you can pop into Google maps/earth to see what the density is:
sbw_interval.kml
Given the amount of DCAPE and strong sunshine today, I'm surprise we aren't in a DY1 slight risk. There's another kicker working through the region this afternoon and it might yield similar results to yesterday.