Looking at the individual GEFS members, I count about 8 that give DC a nice hit, and a handful of others that just barely miss. At 18z there were pretty much no flush hits.
Basically if we want a storm, we want to see an amplified ridge over Alaska and deeper trough in the Central US (he uses hour +144). He thinks the overall pattern might support a better storm than the GEFS mean is indicating.
From looking at the latest GEFS and EPS, I think the bigger risk at this point is that the trough doesn’t dig enough and this slides off to the south and we just get a glancing hit (or none at all).