Looks kinda like a differential heating boundary in the Mid-Atlantic and some other wind shift (vaguely) reflected in the surface obs and the cu field.

As others have noted mid-level lapse rates are pretty terrible, and low-level wind fields are fairly weak. Winds aloft are also pointed pretty close to the orientation of those boundaries.

Many of the HREF member depict the segment of convection in the DC area as being more east-west oriented (which I think might end up being right for the wrong reasons), but if this is the case, that implies the storms in that east-west segment might not stay discrete.