Writing was on the wall last night for this to underperform. The Ohio Valley shortwave was much farther south and less robust than CAMs guidance showed 24 hours ago. GFS actually caught on to this first followed by the HRRR and finally the NAM. Persistent cloud cover has greatly limited our instability - CAPE is less than 1000 J/KG for most N of DC at the moment. For southern Virginia, though, where there has been clearing, CAPE is over 3000 J/KG and there is sufficient speed and directional shear to support isolated supercells. However, the total coverage will be far less than what we expected 24 hours ago.
Unfortunately, this scenario plays out time and time again in this region. I was really looking forward to chasing today after work, oh well